Vulnerability database

954 results · page 4 of 20

• Aug 10, 2026In the Linux kernel, the following vulnerability has been resolved: smb: client: validate DFS referral PathConsumed parse_dfs_referrals() validates that the rCVE-2026-68343 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67Critical 9.1

  In the Linux kernel, the following vulnerability has been resolved: smb: client: validate DFS referral PathConsumed parse_dfs_referrals() validates that the response contains the fixed referral entry array and, on for-next, the per-referral string offsets. However, the response also contains a PathConsumed value that is later used for DFS path parsing. If a malformed response provides a PathConsumed value larger than the search name, later DFS parsing can advance beyond the end of the path. Validate PathConsumed against the search name length before storing it in the parsed referral.

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Aug 10, 2026In the Linux kernel, the following vulnerability has been resolved: ksmbd: defer destroy_previous_session() until after NTLM authentication In ntlm_authenticaCVE-2026-68130 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

  In the Linux kernel, the following vulnerability has been resolved: ksmbd: defer destroy_previous_session() until after NTLM authentication In ntlm_authenticate(), destroy_previous_session() is called using a user pointer resolved from the client-supplied NTLM blob username field before the NTLMv2 response is validated. An authenticated attacker can set the NTLM blob username to match a victim account and set PreviousSessionId to the victim's session ID; destroy_previous_session() destroys the victim's session while ksmbd_decode_ntlmssp_auth_blob() subsequently rejects the request with -EPERM. Move destroy_previous_session() and the prev_id assignment to after ksmbd_decode_ntlmssp_auth_blob() returns success and use sess->user rather than the pre-authentication lookup result. This matches the ordering already used by krb5_authenticate(), where destroy_previous_session() is called only after ksmbd_krb5_authenticate() returns success.

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Aug 10, 2026In the Linux kernel, the following vulnerability has been resolved: ksmbd: validate num_subauth when copying ACE in set_ntacl_dacl set_ntacl_dacl() copies eacCVE-2026-68100 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67High 8.1

  In the Linux kernel, the following vulnerability has been resolved: ksmbd: validate num_subauth when copying ACE in set_ntacl_dacl set_ntacl_dacl() copies each ACE from the attacker-controlled stored security descriptor verbatim into the response DACL without checking sid.num_subauth. The ACE bytes (including an unchecked num_subauth) originate from an authenticated SMB2_SET_INFO(SecInfo=DACL) that is stored raw via ksmbd_vfs_set_sd_xattr(); parse_dacl() rejects a bad ACE with `break` rather than an error, so parse_sec_desc() still returns success and the malformed SD reaches the xattr intact. On a subsequent SMB2_QUERY_INFO(SecInfo=DACL) for an inode carrying a POSIX access ACL, build_sec_desc() -> set_ntacl_dacl() -> set_posix_acl_entries_dacl() walks the copied ACEs and reads ntace->sid.sub_auth[ntace->sid.num_subauth - 1] with num_subauth taken straight from the stored SD. Since sub_auth[] is fixed at SID_MAX_SUB_AUTHORITIES (15), a crafted num_subauth (e.g. 255) drives an out-of-bounds heap read of ~1 KB with an offset fully controlled by an authenticated client. The sibling functions already gate this field: parse_dacl() -- num_subauth == 0 || > SID_MAX_SUB_AUT

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Aug 10, 2026In the Linux kernel, the following vulnerability has been resolved: ksmbd: restore DACL size on check_add_overflow() to avoid malformed ACL check_add_overflowCVE-2026-68099 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

  In the Linux kernel, the following vulnerability has been resolved: ksmbd: restore DACL size on check_add_overflow() to avoid malformed ACL check_add_overflow() unconditionally writes the truncated sum into *d even on overflow, per its contract in include/linux/overflow.h. The four check_add_overflow() guards in set_posix_acl_entries_dacl() and set_ntacl_dacl() break out of the ACE-building loops on overflow, but the truncated *size is then consumed downstream at the end of set_ntacl_dacl(): pndacl->size = cpu_to_le16(le16_to_cpu(pndacl->size) + size); This produces an on-wire NT ACL whose pndacl->size under-reports the bytes actually written by the preceding fill_ace_for_sid()/memcpy() calls, yielding a malformed ACL that can trigger out-of-bounds reads when re-parsed by clients or ksmbd itself. Restore *size to its pre-addition value on each overflow branch (via `*size -= ace_sz` / `size -= nt_ace_size`) so that after the break, *size once again holds the cumulative size of the successfully-written ACEs. The committed ACL is then truncated-but-self-consistent rather than malformed. The ksmbd DACL builders are the only check_add_overflow() sites found where an overflow p

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Aug 10, 2026In the Linux kernel, the following vulnerability has been resolved: ksmbd: bound DACL dedup walk to copied ACEs set_ntacl_dacl() can stop copying ACEs before CVE-2026-68098 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67High 8.8

  In the Linux kernel, the following vulnerability has been resolved: ksmbd: bound DACL dedup walk to copied ACEs set_ntacl_dacl() can stop copying ACEs before consuming the full input DACL when size accounting overflows. When that happens, num_aces reflects only the ACEs that were actually copied into the output DACL, but set_posix_acl_entries_dacl() still receives nt_num_aces and uses it to walk the existing ACE array during dedup. That makes the dedup walk scan past the copied ACE array and inspect buffer tail that does not contain valid ACEs. Split the two meanings currently carried by the NT ACE count. Pass the number of copied NT ACEs to bound the dedup walk, and preserve the original "input DACL had NT ACEs" state separately for the Everyone/default ACL fallback. This keeps the dedup walk aligned with the ACEs that are actually present in the rebuilt DACL.

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Aug 10, 2026In the Linux kernel, the following vulnerability has been resolved: ksmbd: validate ACE size against SID sub-authorities set_ntacl_dacl() validates sid.num_suCVE-2026-68097 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67High 8.8

  In the Linux kernel, the following vulnerability has been resolved: ksmbd: validate ACE size against SID sub-authorities set_ntacl_dacl() validates sid.num_subauth before copying an ACE, but does not verify that the declared ACE size contains all sub-authorities described by that field. An undersized ACE can therefore be copied and later make the POSIX ACL deduplication walk inspect data beyond the copied ACE boundary. The existing initial bound check is also too small. It only ensures that the ACE size field is accessible before set_ntacl_dacl() reads sid.num_subauth farther into the input buffer. Require enough input for the fixed SID header before accessing num_subauth, reject ACEs smaller than that header, and skip ACEs whose declared size cannot contain the complete SID. This makes the validation consistent with the other ACE walk paths.

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Aug 10, 2026In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix path resolution in ksmbd_vfs_kern_path_create The SMB2 open lookup is rooted atCVE-2026-68083 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67Critical 9.1

  In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix path resolution in ksmbd_vfs_kern_path_create The SMB2 open lookup is rooted at the share with LOOKUP_BENEATH, but the create/mkdir/hardlink sink is not: ksmbd_vfs_kern_path_create() builds an absolute path with convert_to_unix_name() and resolves it from AT_FDCWD via start_creating_path(), so a ".." component is walked from the real filesystem root and escapes the export. An authenticated client races a missing path component so the rooted open lookup returns -ENOENT (taking the create branch) while the same component is present (a directory) when the create walk runs; the create then resolves ".." out of the share. Root the create walk at the share like the lookup and rename paths already are: resolve the parent with vfs_path_parent_lookup(..., LOOKUP_BENEATH, &share_conf->vfs_path) and create the final component with start_creating_noperm(). convert_to_unix_name() then has no callers and is removed.

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Aug 6, 2026In the Linux kernel, the following vulnerability has been resolved: smb/client: Fix error code in smb2_aead_req_alloc() The "*num_sgs" variable is a u32 so "ECVE-2026-64598 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67High 8.8

  In the Linux kernel, the following vulnerability has been resolved: smb/client: Fix error code in smb2_aead_req_alloc() The "*num_sgs" variable is a u32 so "ERR_PTR(*num_sgs)" doesn't work. We would have to do something similar to the previous line where it's cast to int and then long. However, it's simpler to store the return in an int ret variable. This bug would eventually result in a crash when dereference the invalid error pointer.

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Aug 6, 2026In the Linux kernel, the following vulnerability has been resolved: smb: client: fix double-free in SMB2_close() replay A response-bearing attempt can return CVE-2026-64597 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67Critical 9.8

  In the Linux kernel, the following vulnerability has been resolved: smb: client: fix double-free in SMB2_close() replay A response-bearing attempt can return a replayable error and free its response buffer. If SMB2_close_init() fails before the next send, cleanup retains the previous buffer type and frees that response again. Reset response bookkeeping before each attempt to prevent the stale free.

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Aug 5, 2026In the Linux kernel, the following vulnerability has been resolved: ksmbd: validate compound request size before reading StructureSize2 When ksmbd validates aCVE-2026-64578 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67High 8.2

  In the Linux kernel, the following vulnerability has been resolved: ksmbd: validate compound request size before reading StructureSize2 When ksmbd validates a compound (chained) SMB2 request, ksmbd_smb2_check_message() reads pdu->StructureSize2 without first checking that the compound element is large enough to contain it. StructureSize2 is a 2-byte field at offset 64 (__SMB2_HEADER_STRUCTURE_SIZE) from the start of each element. The compound-walking logic only guarantees that a full 64-byte SMB2 header is present for the trailing element: when NextCommand is 0, len is reduced to the number of bytes remaining after next_smb2_rcv_hdr_off. A remote client can craft a compound request whose last element has exactly 64 bytes, so the 2-byte StructureSize2 read at offset 64 extends one byte past the receive buffer, producing a slab-out-of-bounds read. BUG: KASAN: slab-out-of-bounds in ksmbd_smb2_check_message (fs/smb/server/smb2misc.c:402) Read of size 2 at addr ffff888012ae31ac by task kworker/0:1/14 The buggy address is located 172 bytes inside of allocated 173-byte region Workqueue: ksmbd-io handle_ksmbd_work Call Trace: ... kasan_report (mm/kasan/report.c:595)

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Jul 25, 2026In the Linux kernel, the following vulnerability has been resolved: smb: client: restrict implied bcc[0] exemption to responses without data area smb2_check_mCVE-2026-64448 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67High 8.2

  In the Linux kernel, the following vulnerability has been resolved: smb: client: restrict implied bcc[0] exemption to responses without data area smb2_check_message() has a long-standing quirk that accepts a response whose calculated length is one byte larger than the bytes actually received ("server can return one byte more due to implied bcc[0]"). This was introduced to accommodate servers that omit the trailing bcc[0] overlap byte when no data area is present. However, the exemption is applied unconditionally, regardless of whether the command actually carries a data area (has_smb2_data_area[]). When a response with a data area is subject to the +1 exemption, the reported data can extend one byte beyond the bytes actually received, yet smb2_check_message() still accepts it. The subsequent decoder then reads past the end of the receive buffer. This is reachable during NEGOTIATE and SESSION_SETUP, before the session is established. The resulting out-of-bounds reads are visible under KASAN when mounting against a non-conforming server; both the SPNEGO/negTokenInit and the NTLMSSP challenge decoders are affected: BUG: KASAN: slab-out-of-bounds in asn1_ber_decoder+0x16a7/0x

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Jul 25, 2026In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free of a deferred file_lock on SMB2_CLOSE then SMB2_CANCEL Commit f5CVE-2026-64437 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67High 8.8

  In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free of a deferred file_lock on SMB2_CLOSE then SMB2_CANCEL Commit f580d27e8928 ("ksmbd: fix use-after-free of a deferred file_lock on double SMB2_CANCEL") made smb2_cancel() skip a work whose state is KSMBD_WORK_CANCELLED, so its cancel_fn cannot be fired a second time. But KSMBD_WORK has three states (ACTIVE, CANCELLED, CLOSED), and the same freeing producer path is reached for CLOSED too: SMB2_CLOSE on the locking handle -> set_close_state_blocked_works() sets the deferred work's state to KSMBD_WORK_CLOSED and wakes the smb2_lock() worker. The worker takes the non-ACTIVE early-exit, locks_free_lock()s the file_lock and, because the state is not KSMBD_WORK_CANCELLED, takes the STATUS_RANGE_NOT_LOCKED branch with "goto out2" -- which, like the cancelled branch, skips release_async_work(). The work stays on conn->async_requests with a live cancel_fn = smb2_remove_blocked_lock pointing at the freed file_lock. A subsequent SMB2_CANCEL for the same AsyncId then passes the KSMBD_WORK_CANCELLED-only guard (its state is KSMBD_WORK_CLOSED), so smb2_cancel() fires cancel_fn again ov

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Jul 25, 2026In the Linux kernel, the following vulnerability has been resolved: coresight: ultrasoc-smb: Fix OOB write in smb_sync_perf_buffer() When the SMB sink is usedCVE-2026-64402 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67High 7.8

  In the Linux kernel, the following vulnerability has been resolved: coresight: ultrasoc-smb: Fix OOB write in smb_sync_perf_buffer() When the SMB sink is used as a perf AUX sink, smb_update_buffer() calls smb_sync_perf_buffer() to copy hardware trace data into the perf AUX ring buffer pages. It derives pg_idx = head >> PAGE_SHIFT from @head, which is handle->head, and indexes dst_pages[pg_idx]. The pg_idx %= nr_pages normalization is only applied after the first loop iteration. This leaves the initial page index underived from the buffer size, which can result in an out-of-bounds write past dst_pages[] when head exceeds the AUX buffer size. Normalize head modulo the AUX buffer size before deriving the page index and offset, mirroring tmc_etr_sync_perf_buffer().

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Jul 25, 2026In the Linux kernel, the following vulnerability has been resolved: smb: client: resolve SWN tcon from live registrations cifs_swn_notify() looks up a witnessCVE-2026-64401 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67High 7.8

  In the Linux kernel, the following vulnerability has been resolved: smb: client: resolve SWN tcon from live registrations cifs_swn_notify() looks up a witness registration by id under cifs_swnreg_idr_mutex, drops the mutex, and then uses the registration's cached tcon pointer. That pointer is not a lifetime reference, and it is not a stable representative once cifs_get_swn_reg() lets multiple tcons for the same net/share name share one registration id. A same-share second mount can keep the cifs_swn_reg alive after the first tcon unregisters and is freed. The registration then still points at the freed first tcon, so taking tc_lock or incrementing tc_count through swnreg->tcon only moves the use-after-free earlier. Taking tc_lock while holding cifs_swnreg_idr_mutex also violates the documented CIFS lock order. Fix this by making the registration store only the stable witness identity: id, net name, share name, and notify flags. When a notify arrives, copy that identity under cifs_swnreg_idr_mutex, drop the mutex, then find and pin a live witness tcon that currently matches the net/share pair under the normal cifs_tcp_ses_lock -> tc_lock order. The notification path uses th

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Jul 25, 2026In the Linux kernel, the following vulnerability has been resolved: ksmbd: prevent path traversal bypass by restricting caseless retry ksmbd_vfs_path_lookup()CVE-2026-64400 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67High 8.6

  In the Linux kernel, the following vulnerability has been resolved: ksmbd: prevent path traversal bypass by restricting caseless retry ksmbd_vfs_path_lookup() enforces LOOKUP_BENEATH to restrict path resolution within the share root. When a crafted path attempts to escape the share boundary using parent-directory components ('..'), vfs_path_parent_lookup() detects this and immediately fails, returning -EXDEV. However, a bug exists in __ksmbd_vfs_kern_path() under caseless mode. The function fails to intercept the -EXDEV error and erroneously falls through to the caseless retry logic, which is intended only for genuinely missing files. During this retry process, the path is reconstructed, leading to an unintended LOOKUP_BENEATH bypass that allows write-capable users to create zero-length files or directories outside the exported share. Fix this by ensuring that the execution only proceeds to the caseless lookup retry when the error is specifically -ENOENT. Any other errors, such as -EXDEV from a path traversal attempt, must be returned immediately.

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Jul 25, 2026In the Linux kernel, the following vulnerability has been resolved: ksmbd: add permission checks for FSCTL_DUPLICATE_EXTENTS_TO_FILE The FSCTL_DUPLICATE_EXTENCVE-2026-64399 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67Critical 9.8

  In the Linux kernel, the following vulnerability has been resolved: ksmbd: add permission checks for FSCTL_DUPLICATE_EXTENTS_TO_FILE The FSCTL_DUPLICATE_EXTENTS_TO_FILE arm of smb2_ioctl() overwrites the destination file's data via vfs_clone_file_range() with neither the share-level KSMBD_TREE_CONN_FLAG_WRITABLE check nor a per-handle fp->daccess check that the other write-bearing arms carry. A client can overwrite destination data on a read-only share, or from a handle opened with only FILE_WRITE_ATTRIBUTES (which still yields an FMODE_WRITE filp). FILE_WRITE_ATTRIBUTES-only destination handle overwrote the file's data via the clone. Add both checks, matching the FSCTL_SET_SPARSE permission fix; require FILE_WRITE_DATA since this writes data.

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Jul 25, 2026In the Linux kernel, the following vulnerability has been resolved: ksmbd: add a permission check for FSCTL_SET_ZERO_DATA FSCTL_SET_ZERO_DATA in smb2_ioctl() CVE-2026-64398 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67High 8.1

  In the Linux kernel, the following vulnerability has been resolved: ksmbd: add a permission check for FSCTL_SET_ZERO_DATA FSCTL_SET_ZERO_DATA in smb2_ioctl() destroys file data via ksmbd_vfs_zero_data() -> vfs_fallocate(PUNCH_HOLE/ZERO_RANGE) after checking only the share-level KSMBD_TREE_CONN_FLAG_WRITABLE, with no per-handle access check. A handle opened with only FILE_WRITE_ATTRIBUTES still yields an FMODE_WRITE filp (FILE_WRITE_ATTRIBUTES is part of FILE_WRITE_DESIRE_ACCESS_LE, so smb2_create_open_flags() opens it O_WRONLY), so the vfs_fallocate FMODE_WRITE check does not stop it; only the missing fp->daccess gate would. Reproduced on mainline 7.1-rc7 with KASAN by an authenticated SMB client: a FILE_WRITE_ATTRIBUTES-only handle zeroed 4096 bytes of file data it had no FILE_WRITE_DATA right to (6/6; a FILE_READ_DATA-only handle was correctly denied). This is the unfixed sibling of commit cc57232cae23 ("ksmbd: fix FSCTL permission bypass by adding a permission check for FSCTL_SET_SPARSE"). Because SET_ZERO_DATA writes data (not an attribute), require FILE_WRITE_DATA.

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Jul 25, 2026In the Linux kernel, the following vulnerability has been resolved: ksmbd: serialize QUERY_DIRECTORY requests per file smb2_query_dir() stores a pointer to itCVE-2026-64397 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67Critical 9.8

  In the Linux kernel, the following vulnerability has been resolved: ksmbd: serialize QUERY_DIRECTORY requests per file smb2_query_dir() stores a pointer to its stack-allocated private data in the ksmbd_file readdir_data. Concurrent QUERY_DIRECTORY requests using the same file handle can overwrite this pointer while an iterate_dir() callback is still using it, resulting in a stack use-after-free. Add a per-file mutex and hold it while accessing the shared directory enumeration state. The lock covers scan restart, dot entry state, readdir_data setup and iteration, and response construction. This prevents another request from replacing readdir_data.private before the current request has finished using it and also serializes the shared file position.

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Jul 25, 2026In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix UAF of struct file_lock in SMB2_LOCK deferred-lock cancellation When a blockingCVE-2026-64396 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67High 8.8

  In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix UAF of struct file_lock in SMB2_LOCK deferred-lock cancellation When a blocking byte-range lock request is deferred in the FILE_LOCK_DEFERRED path, ksmbd registers the asynchronous work into the connection's async_requests list via setup_async_work(). The cancel callback smb2_remove_blocked_lock() holds a reference to the flock. If the lock waiter is subsequently woken up but the work state is no longer KSMBD_WORK_ACTIVE (e.g., due to a concurrent cancellation), the cleanup path calls locks_free_lock(flock) without dequeuing the work from the async_requests list. Concurrently, smb2_cancel() walks the list under conn->request_lock and invokes the cancel callback, which then dereferences the already freed 'flock'. This leads to a slab-use-after-free inside __wake_up_common. Fix this by restructuring the cleanup logic after the worker returns from ksmbd_vfs_posix_lock_wait(). Move list_del(&smb_lock->llist) and release_async_work(work) to the top of the cleanup block. This guarantees that the async work is completely dequeued and serialized under conn->request_lock before locks_free_lock(flock) is calle

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Jul 25, 2026In the Linux kernel, the following vulnerability has been resolved: ksmbd: require source read access for duplicate extents FSCTL_DUPLICATE_EXTENTS_TO_FILE paCVE-2026-64395 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67High 7.5

  In the Linux kernel, the following vulnerability has been resolved: ksmbd: require source read access for duplicate extents FSCTL_DUPLICATE_EXTENTS_TO_FILE passes the source file directly to vfs_clone_file_range() or vfs_copy_file_range() without checking the SMB access mask granted to the source handle. A handle opened with attribute access can consequently be used to copy file contents into an attacker-readable destination. Require FILE_READ_DATA on the source handle before either VFS operation, matching other ksmbd data-copy paths.

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Jul 25, 2026In the Linux kernel, the following vulnerability has been resolved: ksmbd: add a WRITE_DAC/WRITE_OWNER check to SMB2 SET_INFO SECURITY commit cc57232cae23 ("kCVE-2026-64394 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67High 8.8

  In the Linux kernel, the following vulnerability has been resolved: ksmbd: add a WRITE_DAC/WRITE_OWNER check to SMB2 SET_INFO SECURITY commit cc57232cae23 ("ksmbd: fix FSCTL permission bypass by adding a permission check for FSCTL_SET_SPARSE") added a fp->daccess gate to fsctl_set_sparse and noted that "similar handle-level checks exist in other functions but are missing here." The SMB2 SET_INFO SECURITY arm is one of the missing ones, and the most security-relevant: smb2_set_info_sec() calls set_info_sec() with no per-handle access check. set_info_sec() (fs/smb/server/smbacl.c) re-permissions the file: it rewrites owner/group/mode via notify_change(), rewrites the POSIX ACL via set_posix_acl(), and on KSMBD_SHARE_FLAG_ACL_XATTR shares removes and rewrites the Windows security descriptor via ksmbd_vfs_set_sd_xattr(). Every other persistent-mutation arm of the sibling handler smb2_set_info_file() checks fp->daccess first (FILE_WRITE_DATA / FILE_DELETE / FILE_WRITE_EA / FILE_WRITE_ATTRIBUTES); the SECURITY arm — which mutates the access control itself — is the only one with no gate. A client can therefore open a handle with FILE_WRITE_ATTRIBUTES only (no FILE_WRITE_DAC / FILE_WRI

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Jul 25, 2026In the Linux kernel, the following vulnerability has been resolved: ksmbd: run set info with opener credentials SMB2 SET_INFO handlers call path-based VFS helCVE-2026-64393 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67Critical 9.1

  In the Linux kernel, the following vulnerability has been resolved: ksmbd: run set info with opener credentials SMB2 SET_INFO handlers call path-based VFS helpers after checking the access mask granted to the SMB handle. Those helpers perform their owner, inode permission and LSM checks using the current ksmbd worker credentials. Run the complete SET_INFO dispatch with the credentials captured when the handle was opened. This also removes the separate security information credential setup and keeps all SET_INFO classes under one credential scope. Direct override_creds() is used because it can nest with the request credential overrides already used by rename and link helpers.

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Jul 25, 2026In the Linux kernel, the following vulnerability has been resolved: ksmbd: use opener credentials for delete-on-close Delete-on-close can be completed by defeCVE-2026-64392 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67Critical 9.1

  In the Linux kernel, the following vulnerability has been resolved: ksmbd: use opener credentials for delete-on-close Delete-on-close can be completed by deferred or durable handle teardown, where no request work is available. Both the base-file unlink and the ADS xattr removal consequently run with the ksmbd worker credentials and can bypass filesystem permission checks. Run both operations with the credentials captured in struct file when the handle was opened. This preserves the authenticated user's fsuid, fsgid, supplementary groups and capability restrictions at final close.

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Jul 25, 2026In the Linux kernel, the following vulnerability has been resolved: ksmbd: use opener credentials for ADS I/O Alternate data streams are stored as xattrs.CVE-2026-64391 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67Critical 9.8

  In the Linux kernel, the following vulnerability has been resolved: ksmbd: use opener credentials for ADS I/O Alternate data streams are stored as xattrs. Unlike regular file I/O, their read and write paths therefore call VFS xattr helpers which recheck inode permissions and LSM policy using the current task credentials. Run ADS I/O with the credentials captured when the SMB handle was opened.

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Jul 25, 2026In the Linux kernel, the following vulnerability has been resolved: ksmbd: track the connection owning a byte-range lock SMB2_LOCK adds each granted byte-rangCVE-2026-64390 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67High 8.8

  In the Linux kernel, the following vulnerability has been resolved: ksmbd: track the connection owning a byte-range lock SMB2_LOCK adds each granted byte-range lock to both the file lock list and the lock list of the connection which handled the request. The final close and durable handle paths, however, remove the connection list entry while holding fp->conn->llist_lock. With SMB3 multichannel, the connection handling the LOCK request can be different from the connection which opened the file. The entry can therefore be removed under a different spinlock from the one protecting the list it belongs to. A concurrent traversal can then access freed struct ksmbd_lock and struct file_lock objects. Record the connection owning each lock's clist entry and hold a reference to it while the entry is linked. Use that connection and its llist_lock for unlock, rollback, close, and durable preserve. Durable reconnect assigns the new connection as the owner when publishing the locks again.

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Jul 25, 2026In the Linux kernel, the following vulnerability has been resolved: ksmbd: validate NTLMv2 response before updating session key ksmbd_auth_ntlmv2() derives thCVE-2026-64389 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67High 8.2

  In the Linux kernel, the following vulnerability has been resolved: ksmbd: validate NTLMv2 response before updating session key ksmbd_auth_ntlmv2() derives the NTLMv2 session key into sess->sess_key before it verifies the NTLMv2 response. ksmbd_decode_ntlmssp_auth_blob() then continues into KEY_XCH even when ksmbd_auth_ntlmv2() failed. With SMB3 multichannel binding, the failed authentication operates on an existing session and the session setup error path does not expire binding sessions. A client can send a binding session setup with a bad NT proof and KEY_XCH and still modify sess->sess_key before STATUS_LOGON_FAILURE is returned. Relevant path: smb2_sess_setup() -> conn->binding = true -> ntlm_authenticate() -> session_user() -> ksmbd_decode_ntlmssp_auth_blob() -> ksmbd_auth_ntlmv2() -> calc_ntlmv2_hash() -> hmac_md5_usingrawkey(..., sess->sess_key) -> crypto_memneq() returns mismatch -> KEY_XCH arc4_crypt(..., sess->sess_key, ...) -> out_err without expiring the binding session Derive the base session key into a local buffer and copy it to sess->sess_key only after the proof matches. R

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Jul 25, 2026In the Linux kernel, the following vulnerability has been resolved: smb/client: fix chown/chgrp with SMB3 POSIX Extensions Ownership (chown) and group (chgrp)CVE-2026-64388 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67High 7.8

  In the Linux kernel, the following vulnerability has been resolved: smb/client: fix chown/chgrp with SMB3 POSIX Extensions Ownership (chown) and group (chgrp) modifications were being ignored when mounting with SMB3 POSIX Extensions unless CIFS_MOUNT_CIFS_ACL or CIFS_MOUNT_MODE_FROM_SID were also explicitly set. Fix this by checking for posix_extensions in cifs_setattr_nounix() when updating UID and GID, ensuring that id_mode_to_cifs_acl() is called to map and set the ownership/group information on the server.

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Jul 25, 2026In the Linux kernel, the following vulnerability has been resolved: smb: client: fix query directory replay double-free A response-bearing attempt can return CVE-2026-64387 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67Critical 9.8

  In the Linux kernel, the following vulnerability has been resolved: smb: client: fix query directory replay double-free A response-bearing attempt can return a replayable error and free its response buffer. If SMB2_query_directory_init() fails before the next send, cleanup retains the previous buffer type and frees that response again. Reset response bookkeeping before each attempt to prevent the stale free.

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Jul 25, 2026In the Linux kernel, the following vulnerability has been resolved: smb: client: fix query_info() replay double-free A response-bearing attempt can return a rCVE-2026-64386 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67Critical 9.8

  In the Linux kernel, the following vulnerability has been resolved: smb: client: fix query_info() replay double-free A response-bearing attempt can return a replayable error and free its response buffer. If SMB2_query_info_init() fails before the next send, cleanup retains the previous buffer type and frees that response again. Reset response bookkeeping before each attempt to prevent the stale free.

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Jul 25, 2026In the Linux kernel, the following vulnerability has been resolved: smb: client: fix double-free in SMB2_ioctl() replay A response-bearing attempt can return CVE-2026-64385 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67Critical 9.8

  In the Linux kernel, the following vulnerability has been resolved: smb: client: fix double-free in SMB2_ioctl() replay A response-bearing attempt can return a replayable error and free its response buffer. If SMB2_ioctl_init() fails before the next send, cleanup retains the previous buffer type and frees that response again. Reset response bookkeeping before each attempt to prevent the stale free.

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Jul 25, 2026In the Linux kernel, the following vulnerability has been resolved: smb: client: fix change notify replay double-free A response-bearing attempt can return a CVE-2026-64384 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67Critical 9.8

  In the Linux kernel, the following vulnerability has been resolved: smb: client: fix change notify replay double-free A response-bearing attempt can return a replayable error and free its response buffer. If SMB2_notify_init() fails before the next send, cleanup retains the previous buffer type and frees that response again. Reset response bookkeeping before each attempt to prevent the stale free.

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Jul 25, 2026In the Linux kernel, the following vulnerability has been resolved: smb: client: fix double-free in SMB2_flush() replay SMB2_flush() keeps its response bufferCVE-2026-64383 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67Critical 9.8

  In the Linux kernel, the following vulnerability has been resolved: smb: client: fix double-free in SMB2_flush() replay SMB2_flush() keeps its response buffer bookkeeping across replay attempts. If a replayable flush response is received and the retry then fails before cifs_send_recv() stores a replacement response, flush_exit will free the stale response pointer a second time. Reinitialize resp_buftype and rsp_iov at the top of the replay loop so cleanup only acts on response state produced by the current attempt. This fixes a double-free without changing replay handling for successful requests.

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Jul 25, 2026In the Linux kernel, the following vulnerability has been resolved: smb: client: fix double-free in SMB2_open() replay A response-bearing attempt can return aCVE-2026-64382 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67High 8.8

  In the Linux kernel, the following vulnerability has been resolved: smb: client: fix double-free in SMB2_open() replay A response-bearing attempt can return a replayable error and free its response buffer. If SMB2_open_init() fails before the next send, cleanup retains the previous buffer type and frees that response again. Reset response bookkeeping before each attempt to prevent the stale free.

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Jul 25, 2026In the Linux kernel, the following vulnerability has been resolved: smb: client: Fix next buffer leak in receive_encrypted_standard() receive_encrypted_standaCVE-2026-64381 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67High 7.8

  In the Linux kernel, the following vulnerability has been resolved: smb: client: Fix next buffer leak in receive_encrypted_standard() receive_encrypted_standard() allocates next_buffer before checking whether the number of compound PDUs already reached MAX_COMPOUND. If the limit check fails, the function returns immediately and the newly allocated next_buffer is not assigned to server->smallbuf/server->bigbuf, making it leaked. Move the MAX_COMPOUND check before allocating next_buffer.

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Jul 25, 2026In the Linux kernel, the following vulnerability has been resolved: smb: client: harden POSIX SID length parsing posix_info_sid_size() reads sid[1] to obtain CVE-2026-64380 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67High 8.2

  In the Linux kernel, the following vulnerability has been resolved: smb: client: harden POSIX SID length parsing posix_info_sid_size() reads sid[1] to obtain the subauthority count, but its existing boundary check still accepts buffers with only one remaining byte. Require two bytes before reading sid[1] so all client paths that reuse the helper reject truncated POSIX SIDs safely.

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Jul 25, 2026In the Linux kernel, the following vulnerability has been resolved: smb: client: mask server-provided mode to 07777 in modefromsid When modefromsid is active,CVE-2026-64379 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67High 7.1

  In the Linux kernel, the following vulnerability has been resolved: smb: client: mask server-provided mode to 07777 in modefromsid When modefromsid is active, parse_dacl() applies the server-provided sub_auth[2] value from the NFS mode SID to cf_mode without masking to 07777. Apply the correct masking, same as in the read path.

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Jul 25, 2026In the Linux kernel, the following vulnerability has been resolved: smb: client: reject overlapping data areas in SMB2 responses Commit 53b7c271f06b ("smb: clCVE-2026-64257 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67Critical 9.1

  In the Linux kernel, the following vulnerability has been resolved: smb: client: reject overlapping data areas in SMB2 responses Commit 53b7c271f06b ("smb: client: restrict implied bcc[0] exemption to responses without data area") restricted the implied bcc[0] length exception to responses without a data area. However, the overlap handling in __smb2_calc_size() clears data_length, which can make an invalid response appear to have no data area and so qualify for the exception. Track data area overlap separately and reject such responses before applying the length compatibility exceptions.

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Jul 20, 2026In the Linux kernel, the following vulnerability has been resolved: i2c: stub: Reject I2C block transfers with invalid length The I2C_SMBUS_I2C_BLOCK_DATA casCVE-2026-64191 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67High 7.8

  In the Linux kernel, the following vulnerability has been resolved: i2c: stub: Reject I2C block transfers with invalid length The I2C_SMBUS_I2C_BLOCK_DATA case in stub_xfer() uses data->block[0] as the transfer length. The existing check only clamps it to avoid overrunning the chip->words[256] register array, but does not validate it against I2C_SMBUS_BLOCK_MAX (32), which is the limit of the union i2c_smbus_data.block buffer (34 bytes total). The driver is a development/test tool (CONFIG_I2C_STUB=m, not built by default) that must be loaded with a chip_addr= parameter. A local user with access to /dev/i2c-* can issue an I2C_SMBUS ioctl with I2C_SMBUS_I2C_BLOCK_DATA and data->block[0] > 32, causing stub_xfer() to read or write past the end of the union i2c_smbus_data.block buffer: BUG: KASAN: stack-out-of-bounds in stub_xfer (drivers/i2c/i2c-stub.c:223) Read of size 1 at addr ffff88800abcfd92 by task exploit/81 Call Trace: <TASK> stub_xfer (drivers/i2c/i2c-stub.c:223) __i2c_smbus_xfer (drivers/i2c/i2c-core-smbus.c:593) i2c_smbus_xfer (drivers/i2c/i2c-core-smbus.c:536) i2cdev_ioctl_smbus (drivers/i2c/i2c-dev.c:391) i2cdev_ioctl (drivers/i2c/i2c-dev.c:478) __x64_

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Jul 19, 2026In the Linux kernel, the following vulnerability has been resolved: ksmbd: close durable scavenger races against m_fp_list lookups ksmbd_durable_scavenger() hCVE-2026-64142 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67Critical 9.8

  In the Linux kernel, the following vulnerability has been resolved: ksmbd: close durable scavenger races against m_fp_list lookups ksmbd_durable_scavenger() has two related races against any walker that iterates f_ci->m_fp_list, including ksmbd_lookup_fd_inode() (used by ksmbd_vfs_rename) and the share-mode checks in fs/smb/server/smb_common.c. (1) fp->node list-head reuse. Durable-preserved handles can remain linked on f_ci->m_fp_list after session teardown so share-mode checks still see them while the handle is reconnectable. The scavenger collected expired handles by adding fp->node to a local scavenger_list after removing them from the global durable idr. Because fp->node is the same list_head used by m_fp_list, list_add(&fp->node, &scavenger_list) overwrites the m_fp_list links and corrupts both lists. CONFIG_DEBUG_LIST can report this on the share-mode walk path. (2) Refcount race against m_fp_list walkers. The scavenger qualifies an expired durable handle with atomic_read(&fp->refcount) > 1 and fp->conn under global_ft.lock, removes fp from global_ft, then drops global_ft.lock before unlinking fp from m_fp_list and freeing it. During that gap fp is still linked on m_

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Jul 19, 2026In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix null pointer dereference in compare_guid_key() session_fd_check() walks the perCVE-2026-64141 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67High 7.5

  In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix null pointer dereference in compare_guid_key() session_fd_check() walks the per-inode m_op_list during durable-handle session teardown and sets op->conn = NULL for every opinfo whose conn matched the closing session's connection. The matching opinfo, however, stays linked in its per-ClientGuid lease_table_list entry's lb->lease_list because destroy_lease_table() only runs on full TCP-connection teardown, not on SESSION_LOGOFF. If the same TCP connection then negotiates a fresh session with the same ClientGuid (ClientGuid is bound to NEGOTIATE, not the session, and is unchanged across LOGOFF + SETUP) and issues a SMB2 CREATE with a lease context on a different inode, find_same_lease_key() walks lb->lease_list, reaches the stale opinfo, and calls compare_guid_key(), which unconditionally dereferences opinfo->conn->ClientGUID. The conn pointer is NULL and the kernel panics. Reproducer requires only a successful SMB2 SESSION_SETUP and a share configured with 'durable handles = yes'. KASAN report on mainline 70390501d194: general protection fault, probably for non-canonical address 0xdffffc0000000069

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Jul 19, 2026In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix null pointer dereference in proc_show_files() When a SMB2 client opens a file wCVE-2026-64140 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67High 7.5

  In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix null pointer dereference in proc_show_files() When a SMB2 client opens a file with a durable v2 handle and then issues SMB2 SESSION_LOGOFF, session_fd_check() clears fp->tcon = NULL on the reconnectable file pointer but leaves the fp registered in global_ft.idr until the durable scavenger fires (up to fp->durable_timeout seconds later). During that window any read of /proc/fs/ksmbd/files (mode 0400) panics the kernel because proc_show_files() walks global_ft.idr and unconditionally dereferences fp->tcon->id with no NULL guard. Reproducer requires only a successful SMB2 SESSION_SETUP and a share configured with 'durable handles = yes'. KASAN report on mainline 70390501d194: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] RIP: 0010:proc_show_files+0x118/0x740 Call Trace: proc_show_files+0x118/0x740 seq_read_iter+0x4ef/0xe10 proc_reg_read_iter+0x1b7/0x280 ... Guard the dereference. A durable-disconnected fp legitimately has no tcon; report its tree id as

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Jul 19, 2026In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix SID memory leak in set_posix_acl_entries_dacl() on overflow Commit 299f962c0b02CVE-2026-64139 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67Medium 5.5

  In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix SID memory leak in set_posix_acl_entries_dacl() on overflow Commit 299f962c0b02 ("ksmbd: use check_add_overflow() to prevent u16 DACL size overflow") added check_add_overflow() guards that break out of the ACE-building loops in set_posix_acl_entries_dacl() when the accumulated DACL size would wrap past 65535. However, each iteration allocates a struct smb_sid via kmalloc_obj() at the top of the loop and relies on the kfree(sid) call at the end of the loop body (the 'pass_same_sid' label in the first loop, and the explicit kfree at the tail of the second loop) to release it. The newly introduced 'break' statements bypass those kfree() calls, leaking the sid buffer every time an overflow is detected. A malicious or malformed file with enough POSIX ACL entries to trip the overflow check will leak one or more struct smb_sid allocations on every request that touches the file's DACL, providing a trivial kernel memory exhaustion vector. Free sid before breaking out of the loops to plug the leak.

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Jul 19, 2026In the Linux kernel, the following vulnerability has been resolved: ksmbd: validate SID in parent security descriptor during ACL inheritance Introduce smb_valCVE-2026-64138 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67High 8.8

  In the Linux kernel, the following vulnerability has been resolved: ksmbd: validate SID in parent security descriptor during ACL inheritance Introduce smb_validate_ntsd_sid() helper to safely validate Owner SID and Group SID inside the NT Security Descriptor (smb_ntsd) retrieved from the parent directory.

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Jul 19, 2026In the Linux kernel, the following vulnerability has been resolved: smb: client: require net admin for CIFS SWN netlink CIFS_GENL_CMD_SWN_NOTIFY is the userspCVE-2026-64137 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67High 7.8

  In the Linux kernel, the following vulnerability has been resolved: smb: client: require net admin for CIFS SWN netlink CIFS_GENL_CMD_SWN_NOTIFY is the userspace witness-notify command. The intended sender is the cifs.witness helper, but the generic-netlink operation currently has no capability flag, so any local process can send RESOURCE_CHANGE or CLIENT_MOVE notifications to the in-kernel witness handler. The same family exposes CIFS_GENL_MCGRP_SWN without multicast-group capability flags. Register messages sent to that group include the witness registration id and, for NTLM-authenticated mounts, the username, domain, and password attributes copied from the CIFS session. An unprivileged local process should not be able to join that group and receive those messages. Require CAP_NET_ADMIN for incoming SWN_NOTIFY commands with GENL_ADMIN_PERM, and require CAP_NET_ADMIN over the network namespace for joining the SWN multicast group with GENL_MCAST_CAP_NET_ADMIN. The cifs.witness service runs with the privileges needed for both operations.

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Jul 19, 2026In the Linux kernel, the following vulnerability has been resolved: smb: client: protect tc_count increment in smb2_find_smb_sess_tcon_unlocked() Commit 96c4aCVE-2026-64136 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67Critical 9.8

  In the Linux kernel, the following vulnerability has been resolved: smb: client: protect tc_count increment in smb2_find_smb_sess_tcon_unlocked() Commit 96c4af418586 ("cifs: Fix locking usage for tcon fields") refactored cifs code to change cifs_tcp_ses_lock for tc_lock around tc_count changes. There was missing lock around tc_count increment inside smb2_find_smb_sess_tcon_unlocked().

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Jul 19, 2026In the Linux kernel, the following vulnerability has been resolved: hwmon: (pmbus/adm1266) widen blackbox-info buffer to I2C_SMBUS_BLOCK_MAX adm1266_nvmem_reaCVE-2026-64135 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67Medium 5.5

  In the Linux kernel, the following vulnerability has been resolved: hwmon: (pmbus/adm1266) widen blackbox-info buffer to I2C_SMBUS_BLOCK_MAX adm1266_nvmem_read_blackbox() declares a 5-byte stack buffer and passes it to i2c_smbus_read_block_data() to retrieve the 4-byte BLACKBOX_INFO response. i2c_smbus_read_block_data() does not honour caller buffer sizes -- it memcpy()s data.block[0] bytes from the SMBus transaction (where data.block[0] is the length byte returned by the slave device, up to I2C_SMBUS_BLOCK_MAX = 32): memcpy(values, &data.block[1], data.block[0]); If the device returns any block length above 5, the call overflows the caller's 5-byte stack buffer before the post-call if (ret != 4) return -EIO; check has a chance to reject the response. Widen the local buffer to I2C_SMBUS_BLOCK_MAX so the helper has room for any well-formed SMBus block response, matching the convention used by the other i2c_smbus_read_block_data() callers in this driver.

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Jul 19, 2026In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix durable reconnect error path file lifetime After a durable reconnect succeeds, CVE-2026-64016 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67Critical 9.8

  In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix durable reconnect error path file lifetime After a durable reconnect succeeds, ksmbd_reopen_durable_fd() republishes the same ksmbd_file into the session volatile-id table. If smb2_open() then takes a later error path, cleanup first calls ksmbd_fd_put(work, fp) and then unconditionally calls ksmbd_put_durable_fd(dh_info.fp). In this case fp and dh_info.fp are the same object. The first put drops the reconnect lookup reference, but the final durable put can run __ksmbd_close_fd(NULL, fp). Because the final close is not session-aware, it can free the file object without removing the volatile-id entry that was just published into the session table. Use the session-aware put for the final reconnect drop when the reconnect had already succeeded and the error path is cleaning up the republished file. Earlier reconnect failures, before fp is assigned to dh_info.fp, keep using the durable-only put path.

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Jul 19, 2026In the Linux kernel, the following vulnerability has been resolved: ksmbd: OOB read regression in smb_check_perm_dacl() ACE-walk loops Commit d07b26f39246 ("kCVE-2026-63909 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67High 8.1

  In the Linux kernel, the following vulnerability has been resolved: ksmbd: OOB read regression in smb_check_perm_dacl() ACE-walk loops Commit d07b26f39246 ("ksmbd: require minimum ACE size in smb_check_perm_dacl()") introduced a transposed bounds check: if (offsetof(struct smb_ace, sid) + aces_size < CIFS_SID_BASE_SIZE) Since offsetof(..sid) is 8 and CIFS_SID_BASE_SIZE is 8, this evaluates to `aces_size < 0`. Because `aces_size` is always non-negative, this check becomes dead code and never breaks the loop. Worse, that commit removed the old 4-byte guard, meaning the loop now reads `ace->size` (offset 2) even when `aces_size` is 0-3 bytes. This re-opens a 2-byte heap out-of-bounds (OOB) read past the pntsd allocation during subsequent SMB2_CREATE operations. Fix this by properly transposing the comparison to require at least 16 bytes (8-byte offset + 8-byte SID base), matching the correct form used in smb_inherit_dacl().

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Jul 19, 2026In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix out-of-bounds read in smb_check_perm_dacl() The permission-check ACE walk in smCVE-2026-53390 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67High 8.1

  In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix out-of-bounds read in smb_check_perm_dacl() The permission-check ACE walk in smb_check_perm_dacl() validates the ACE header size and caps sid.num_subauth at SID_MAX_SUB_AUTHORITIES, but it never checks that ace->size is actually large enough to contain num_subauth sub-authorities before compare_sids() dereferences them. CIFS_SID_BASE_SIZE covers the SID header up to but excluding the sub_auth[] array, and offsetof(struct smb_ace, sid) is the ACE header, so the existing guards only guarantee the 8-byte SID base, i.e. zero sub-authorities. compare_sids() then reads ace->sid.sub_auth[i] for i < min(local_sid->num_subauth, ace->sid.num_subauth). The local comparison SIDs (sid_everyone, sid_unix_NFS_mode, and the id_to_sid() result) always have at least one sub-authority, and an attacker controls the ACE revision and authority bytes (which lie within the in-bounds SID base), so they can match one of those SIDs and force the sub_auth read. A crafted ACE with size == 16 and num_subauth >= 1 placed at the tail of the security descriptor therefore causes a heap out-of-bounds read of up to SID_MAX_SUB_AUTHORIT

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

• Jul 19, 2026In the Linux kernel, the following vulnerability has been resolved: ksmbd: reject non-VALID session in compound request branch smb2_check_user_session() takesCVE-2026-53383 · Computers, phones & browsers · Linux · reported by 416baaa9-dc9f-4396-8d5f-8c081fb06d67High 7.5

  In the Linux kernel, the following vulnerability has been resolved: ksmbd: reject non-VALID session in compound request branch smb2_check_user_session() takes a shortcut for any operation that is not the first in a COMPOUND request: it reuses work->sess (the session bound by the first operation) and validates only the SessionId, then returns "valid". It never re-checks work->sess->state == SMB2_SESSION_VALID, and a SessionId of 0xFFFFFFFFFFFFFFFF (ULLONG_MAX, the MS-SMB2 related-operation value) skips even the id comparison. The standalone path (ksmbd_session_lookup_all() plus the SESSION_SETUP state machine) does enforce the VALID state; the compound branch bypasses all of it. A SESSION_SETUP carrying only an NTLM Type-1 (NtLmNegotiate) blob publishes a fresh SMB2_SESSION_IN_PROGRESS session whose sess->user is still NULL (->user is assigned later, by ntlm_authenticate()). Used as operation 1 of a COMPOUND with operation 2 = TREE_CONNECT (related, SessionId=ULLONG_MAX, \\host\IPC$), the tree-connect then runs on that IN_PROGRESS session and reaches ksmbd_ipc_tree_connect_request(), which dereferences user_name(sess->user) with sess->user == NULL (transport_ipc.c:687/701/704) ->

  Product

  Linux

  What to do

  Apply the vendor’s update. The NVD record links to the advisory.

  Full record and what to do →NVD recordgit.kernel.orggit.kernel.org

Where this comes from: the exploited list is CISA’s Known Exploited Vulnerabilities catalog. Everything else is the whole National Vulnerability Database, where each record is published by the team that found the bug (Wordfence, Patchstack, WPScan, the vendors themselves and others); we show who. Exploit odds are FIRST’s EPSS, updated daily. Titles and categories are ours, so check the linked record before acting on a detail. For a write-up of the big ones, see our advisories. Every vendor, and every WordPress plugin and theme with a recorded flaw, also has its own page. All of it is free to reuse as JSON, CSV or RSS.