Updated 6 h ago

Vulnerability database

Every flaw the U.S. government’s cybersecurity agency (CISA) has confirmed attackers are using, plus the new WordPress plugin and theme bugs published each day, sorted by what they mean for a small business. We refresh it twice a day. If you see something your website or office runs, tell us.

1,762exploited flaws on CISA’s list

34added in the last 30 days

303new WordPress flaws this week

390,007entries in the database

201 results · page 1 of 5

Oct 28, 2026Allocation of Resources Without Limits or Throttling vulnerability in the HTTP/2 request body reader of mtrudel bandit allows an unauthenticated remote attackerCVE-2026-116078 · Other software · mtrudel · reported by 6b3ad84c-e1a6-4bf7-a703-f496b71e49dbHigh 8.7
Allocation of Resources Without Limits or Throttling vulnerability in the HTTP/2 request body reader of mtrudel bandit allows an unauthenticated remote attacker to exhaust server memory via a request body sent as many 1-byte DATA frames. do_read_data/5 in lib/bandit/http2/stream.ex keeps every DATA frame payload as its own list element until the read returns. The :length option of read_body/2 counts body bytes, not frames, so a body of 1-byte frames costs a list cell and a binary term per byte. Interleaving the frames across up to 500 concurrent streams per connection keeps each stream consuming its frames as they arrive; in the reporter's test, 100 streams held 25 to 40 MiB of stream process memory for 5 MB sent. Only routes whose Plug reads the request body are affected, which includes any route behind Plug.Parsers. This issue affects bandit: from 0.3.1 before 1.14.1.
Product
bandit
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record cna.erlef.org github.com
Oct 26, 2026Allocation of Resources Without Limits or Throttling vulnerability in the HTTP/2 request body reader of mtrudel bandit allows an unauthenticated remote attackerCVE-2026-115269 · Other software · mtrudel · reported by 6b3ad84c-e1a6-4bf7-a703-f496b71e49dbHigh 8.7
Allocation of Resources Without Limits or Throttling vulnerability in the HTTP/2 request body reader of mtrudel bandit allows an unauthenticated remote attacker to hold stream processes open indefinitely via WINDOW_UPDATE or empty SETTINGS frames sent while a Plug reads the request body. Bandit.HTTP2.Stream.do_read_data/4 in lib/bandit/http2/stream.ex waits for each frame with a fresh read_timeout. A stream WINDOW_UPDATE, or the zero-delta window update that every empty SETTINGS frame delivers to all streams, ends the wait without delivering any body data, and the loop starts a new full countdown. A client that sends one of these 9-byte frames before each countdown expires keeps read_body blocked, together with the stream process and whatever the application holds while reading, for as long as it likes. This issue affects bandit: from 1.4.0 before 1.14.0.
Product
bandit
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record cna.erlef.org github.com
Oct 26, 2026Improper Cleanup on Thrown Exception vulnerability in the HTTP/2 handler of mtrudel bandit allows an unauthenticated remote attacker to bypass per-connection reCVE-2026-111103 · Other software · mtrudel · reported by 6b3ad84c-e1a6-4bf7-a703-f496b71e49dbHigh 8.2
Improper Cleanup on Thrown Exception vulnerability in the HTTP/2 handler of mtrudel bandit allows an unauthenticated remote attacker to bypass per-connection resource limits via a single TCP write that carries several frames, one of which raises a stream error. When a frame raises StreamError partway through a chunk, Bandit.HTTP2.Handler.handle_data/3 sends RST_STREAM and continues with the connection state from before the chunk, dropping the rest of it. Streams opened by earlier frames in the chunk keep running their Plug calls, but the stream counts, last_stream_id, the rapid-reset timestamps, the HPACK decoder state and the buffer roll back, so max_concurrent_streams, max_requests and the rapid-reset limiter never see those streams. A client that sends one HEADERS frame more than max_concurrent_streams in each write has the extra refused and the others forgotten: with a limit of 10, five such writes run 50 Plug calls at once. This issue affects bandit: from 1.9.0 before 1.14.0.
Product
bandit
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record cna.erlef.org github.com
Oct 26, 2026Allocation of Resources Without Limits or Throttling vulnerability in the HTTP/2 implementation of mtrudel bandit allows an unauthenticated remote attacker to gCVE-2026-110499 · Other software · mtrudel · reported by 6b3ad84c-e1a6-4bf7-a703-f496b71e49dbHigh 8.7
Allocation of Resources Without Limits or Throttling vulnerability in the HTTP/2 implementation of mtrudel bandit allows an unauthenticated remote attacker to grow per-connection memory and CPU cost without bound via a large SETTINGS_HEADER_TABLE_SIZE. Bandit resizes its HPACK encoder table to whatever size the client advertises, up to 2^32-1 bytes, and indexes response headers into it. Because responses carry distinct values such as date or content-length, nothing is evicted and the table grows with every response for the life of the connection, while each lookup scans it linearly. The SETTINGS handling in Bandit.HTTP2.Connection (lib/bandit/http2/connection.ex) passes remote_settings.header_table_size to HPAX.resize/2 with no server-side cap, and encode_headers encodes every response header as :store. Serving N responses on one connection therefore costs O(N²) CPU in the connection process. This issue affects bandit: from 0.3.6 before 1.14.0.
Product
bandit
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record cna.erlef.org github.com
Oct 26, 2026Improper Handling of Highly Compressed Data (Data Amplification) vulnerability in the HTTP/2 implementation of mtrudel bandit allows an unauthenticated remote aCVE-2026-109584 · Other software · mtrudel · reported by 6b3ad84c-e1a6-4bf7-a703-f496b71e49dbHigh 8.7
Improper Handling of Highly Compressed Data (Data Amplification) vulnerability in the HTTP/2 implementation of mtrudel bandit allows an unauthenticated remote attacker to exhaust server memory via a small HPACK-compressed HEADERS block. The block stores one large cookie value in the HPACK dynamic table and then references it tens of thousands of times with 1-byte indexed fields. In the reporter's run, a 49 KB block made a server with default settings allocate a 183 MB cookie binary before any application code ran, and every concurrent stream can repeat the cost. Bandit.HTTP2.Connection caps only the compressed block (max_header_block_size), and its check of the decoded list against max_header_list_size never fires because that setting defaults to :infinity. combine_cookie_crumbs/1 in lib/bandit/http2/stream.ex then joins every crumb into one binary. This issue affects bandit: from 0.3.3 before 1.14.0.
Product
bandit
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record cna.erlef.org github.com
Oct 26, 2026Inefficient Algorithmic Complexity vulnerability in the HTTP/2 implementation of mtrudel bandit allows an unauthenticated remote attacker to exhaust server CPU CVE-2026-108529 · Other software · mtrudel · reported by 6b3ad84c-e1a6-4bf7-a703-f496b71e49dbHigh 8.7
Inefficient Algorithmic Complexity vulnerability in the HTTP/2 implementation of mtrudel bandit allows an unauthenticated remote attacker to exhaust server CPU via small SETTINGS or connection-level WINDOW_UPDATE frames. The attacker opens thousands of streams whose responses block on the connection send window, then sends cheap frames that each make the server walk the whole queue of blocked sends. In the reporter's run, with 3,000 blocked streams a single 9-byte SETTINGS frame took 133 ms to process. do_pending_sends/2 in lib/bandit/http2/connection.ex retries every queued send and, before each retry, removes that entry from the queue with List.delete/2, so one frame costs O(n²) list operations for n blocked streams. max_concurrent_streams defaults to :infinity, so the attacker chooses n. This issue affects bandit: from 0.3.4 before 1.14.0.
Product
bandit
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record cna.erlef.org github.com
Oct 26, 2026Allocation of Resources Without Limits or Throttling vulnerability in the HTTP/2 implementation of mtrudel bandit allows an unauthenticated remote attacker to eCVE-2026-108525 · Other software · mtrudel · reported by 6b3ad84c-e1a6-4bf7-a703-f496b71e49dbHigh 8.7
Allocation of Resources Without Limits or Throttling vulnerability in the HTTP/2 implementation of mtrudel bandit allows an unauthenticated remote attacker to exhaust server memory via DATA frames sent past the advertised receive window. The attacker requests a response larger than the 65,535-byte initial window and withholds WINDOW_UPDATE, so the stream process blocks while sending and stops reading, then floods small DATA frames on that stream. Every frame is queued in the stream's mailbox until the BEAM node runs out of memory. Bandit.HTTP2.Connection.handle_frame/3 in lib/bandit/http2/connection.ex forwards each DATA frame to the stream process without consulting the receive window, and Bandit.HTTP2.FlowControl.compute_recv_window/2 replenishes the window as data arrives rather than as it is consumed, and never answers a violation with FLOW_CONTROL_ERROR. This issue affects bandit: from 0.3.1 before 1.14.0.
Product
bandit
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record cna.erlef.org github.com
Oct 26, 2026A malicious or compromised HTTP/2 server withholding SETTINGS ACK can send RST_STREAM on a completed stream, planting a null pointer, and then send a PUSH_PROMICVE-2026-96432 · Other software · qt · reported by a59d8014-47c4-4630-ab43-e1b13cbe58e3Low 2.1
A malicious or compromised HTTP/2 server withholding SETTINGS ACK can send RST_STREAM on a completed stream, planting a null pointer, and then send a PUSH_PROMISE for that stream, causing a null pointer dereference in the QNetworkAccessManager class of the Qt Network module that crashes the application.
Product
qt
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record codereview.qt-project.org wiki.qt.io
Oct 23, 2026A use-after-free vulnerability in the Qt QNetworkAccessManager HTTP/2 client support of the Qt Network module allows a malicious or compromised HTTP/2 server toCVE-2026-95620 · Other software · qt · reported by a59d8014-47c4-4630-ab43-e1b13cbe58e3Low 2.1
A use-after-free vulnerability in the Qt QNetworkAccessManager HTTP/2 client support of the Qt Network module allows a malicious or compromised HTTP/2 server to cause the client application to crash, affecting availability.
Product
qt
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record codereview.qt-project.org wiki.qt.io
Oct 21, 2026HAProxy 3.2 before 3.4.6 allows a remote unauthenticated attacker to cause a denial of service (worker-thread CPU exhaustion) via a truncated HTTP/2 PING frame.CVE-2026-110353 · Other software · HAProxy · reported by MITREHigh 7.5
HAProxy 3.2 before 3.4.6 allows a remote unauthenticated attacker to cause a denial of service (worker-thread CPU exhaustion) via a truncated HTTP/2 PING frame. h2c_handle_ping in src/mux_h2.c does not check for a short read, unlike the other H2 frame handlers. Because the incomplete frame cannot be processed, its data is never consumed, and the H2 multiplexer tasklet is repeatedly woken by that pending data without making progress. The CPU spins until timeout http-request closes the connection, and an attacker opening many such connections can sustain high CPU usage.
Product
HAProxy
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record git.haproxy.org
Oct 21, 2026Apache Traffic Server can be used to exhaust an HTTP/1.1 origin's worker pool via a malformed padded HTTP/2 DATA frame.CVE-2026-111808 · Websites & servers · Apache Software Foundation · reported by security@apache.orgHigh 7.7
Apache Traffic Server can be used to exhaust an HTTP/1.1 origin's worker pool via a malformed padded HTTP/2 DATA frame. This issue affects Apache Traffic Server: from 8.0.0 through 8.1.11, from 9.0.0 through 9.2.15, from 10.0.0 through 10.1.4, 10.2.0. Users are recommended to upgrade to version 9.2.16, 10.1.5, or 10.2.1, which fix the issue.
Product
Apache Traffic Server
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record lists.apache.org
Oct 21, 2026Apache Traffic Server can be used to exhaust an HTTP/1.1 origin's worker pool via a truncated HTTP/2 Content-Length value.CVE-2026-111805 · Websites & servers · Apache Software Foundation · reported by security@apache.orgHigh 7.7
Apache Traffic Server can be used to exhaust an HTTP/1.1 origin's worker pool via a truncated HTTP/2 Content-Length value. This issue affects Apache Traffic Server: from 8.0.0 through 8.1.11, from 9.0.0 through 9.2.15, from 10.0.0 through 10.1.4, 10.2.0. Users are recommended to upgrade to version 9.2.16, 10.1.5, or 10.2.1, which fix the issue.
Product
Apache Traffic Server
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record lists.apache.org
Oct 21, 2026Uncontrolled resource consumption in the HTTP/2 (h2) receive path of Apache bRPC (version < 1.18.0) on all platforms allows a remote unauthenticated attacker toCVE-2026-78058 · Websites & servers · Apache Software Foundation · reported by security@apache.org
Uncontrolled resource consumption in the HTTP/2 (h2) receive path of Apache bRPC (version < 1.18.0) on all platforms allows a remote unauthenticated attacker to crash the server or grow its memory without bound by sending crafted HTTP/2 frames. Root Cause: The h2 parser, enabled by default on every bRPC server port and used by h2/gRPC clients, trusts the peer to respect receive-side limits that bRPC advertises but never enforces: 1. SETTINGS_MAX_CONCURRENT_STREAMS defaulted to unlimited and was never checked on the server, letting a peer pin an unbounded number of pending streams per connection (~100x memory amplification). 2. SETTINGS_MAX_HEADER_LIST_SIZE defaulted to unlimited and was never enforced; 1-byte HPACK indexed references amplify a small HEADERS frame ~4000x into an unbounded decoded header list ("HPACK bomb"), and a never-completed HEADERS/CONTINUATION block accumulates memory without limit. 3. Control-frame acks (PING/SETTINGS acks, RST_STREAM, GOAWAY, WINDOW_UPDATE) unconditionally bypassed the -socket_max_unwritten_bytes write cap, so a PING flood combined with withheld TCP reads grew the connection buffer without the documented bound. 4. The HPACK dynamic table si
Product
Apache bRPC
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record lists.apache.org
Oct 21, 2026A reachable-assertion flaw in the HPACK header-compression decoder of the HTTP/2 (h2/gRPC) stack in Apache bRPC (version < 1.18.0) on all platforms allows a remCVE-2026-78048 · Websites & servers · Apache Software Foundation · reported by security@apache.org
A reachable-assertion flaw in the HPACK header-compression decoder of the HTTP/2 (h2/gRPC) stack in Apache bRPC (version < 1.18.0) on all platforms allows a remote attacker to crash the server process by sending a crafted sequence of HPACK headers, resulting in a denial of service. Root Cause: In src/brpc/details/hpack.cpp, IndexTable::Init sizes the dynamic-table ring buffer as num_headers = max_size / (32 + 2), i.e. it assumes a minimum table entry of 34 bytes (name >= 1 byte + value >= 1 byte + 32 bytes of overhead). However, RFC 7541 section 4.1 specifies that the minimum entry size is 33 bytes, because the value may be empty (name >= 1 byte + value == 0 + 32 bytes). For the default 4096-byte table this allocates only 120 slots (4096/34). Eviction in AddHeader is driven by byte usage (_max_size), not by slot count, so a peer can add 121 minimal 33-byte entries (121*33 = 3993 <= 4096) without triggering eviction. The 121st AddHeader then hits CHECK(!_header_queue.full()), which aborts the process. Affected Scenarios: Use a bRPC server that serves HTTP/2 or gRPC requests (e.g. via the h2 protocol) from an untrusted network. The malicious header block is processed during HPACK d
Product
Apache bRPC
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record lists.apache.org
Oct 21, 2026Apache bRPC versions before 1.18.0 do not consistently enforce the configured max_body_size limit in non-progressive HTTP/1 and HTTP/2 parsing and in memcache aCVE-2026-61902 · Websites & servers · Apache Software Foundation · reported by security@apache.org
Apache bRPC versions before 1.18.0 do not consistently enforce the configured max_body_size limit in non-progressive HTTP/1 and HTTP/2 parsing and in memcache and couchbase response parsing. A remote unauthenticated peer can cause an affected process to buffer message data beyond the configured limit, which may lead to memory exhaustion and denial of service. Users should upgrade to 1.18.0 or apply the patch from PR https://github.com/apache/brpc/pull/3382 . The fix rejects oversized buffered HTTP bodies, returns HTTP 413 for HTTP/1 requests, resets oversized HTTP/2 streams, and rejects oversized memcache and couchbase responses from their declared lengths. Progressive HTTP reading remains supported because it uses bounded buffering.
Product
Apache bRPC
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record lists.apache.org
Oct 21, 2026Integer underflow and out-of-bounds read in the HTTP/2 server DATA frame parser in Apache bRPC allows an unauthenticated remote attacker to cause denial of servCVE-2026-56386 · Websites & servers · Apache Software Foundation · reported by security@apache.orgHigh 7.5
Integer underflow and out-of-bounds read in the HTTP/2 server DATA frame parser in Apache bRPC allows an unauthenticated remote attacker to cause denial of service by sending a malformed DATA frame with the PADDED flag set and a zero-length payload. Root Cause: The HTTP/2 DATA frame handler computed the fragment size from the attacker-controlled payload length and, when the PADDED flag was present, decremented the fragment size before ensuring that the frame contained the mandatory pad length byte. A zero-length padded DATA frame could therefore underflow the unsigned fragment size and read the pad length byte past the end of the frame buffer. Affected Scenarios: Apache bRPC servers that accept HTTP/2 traffic are affected when a remote client can send crafted HTTP/2 frames to the server. HTTP/2 may be reached through cleartext h2c detection on an HTTP port or through TLS ALPN negotiation. How to Fix: (Choose one of the following options) 1. Upgrade Apache bRPC to version 1.18.0, which fixes this issue. 2. Apply this patch: https://github.com/apache/brpc/pull/3325 Note: The fix validates that a padded DATA frame has enough payload bytes for the pad length field before decremen
Product
Apache bRPC
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record lists.apache.org
Oct 21, 2026Uncontrolled recursion in the HTTP/2 HPACK decoder in Apache bRPC before 1.18.0 allows remote attackers to cause denial of service by sending a crafted HTTP/2 hCVE-2026-54425 · Websites & servers · Apache Software Foundation · reported by security@apache.org
Uncontrolled recursion in the HTTP/2 HPACK decoder in Apache bRPC before 1.18.0 allows remote attackers to cause denial of service by sending a crafted HTTP/2 header block containing many consecutive Dynamic Table Size Update entries. Each update was decoded by recursively invoking the HPACK decoder, which could exhaust the thread stack before a header field or end of input was reached. Root Cause: The bRPC HPACK decoder recursively decoded the next entry after processing a Dynamic Table Size Update. The decoder did not bound the recursion depth, so a long sequence of update entries could consume excessive stack space. Affected Scenarios: Use bRPC with the built-in HTTP/2 implementation to accept HTTP/2 traffic from an untrusted network. How to Fix: 1. Upgrade bRPC to version 1.18.0, which fixes this issue. 2. Apply this patch: https://github.com/apache/brpc/pull/3343 Note: The fix changes HPACK Dynamic Table Size Update decoding to use iterative parsing instead of recursive parsing.
Product
Apache bRPC
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record lists.apache.org
Oct 20, 2026Incorrect object recycling and re-use vulnerability in Apache Tomcat affecting HTTP/2 processing of asynchronous servlets can trigger request and/or response miCVE-2026-101356 · Websites & servers · Apache Software Foundation · reported by security@apache.orgCritical 9.1
Incorrect object recycling and re-use vulnerability in Apache Tomcat affecting HTTP/2 processing of asynchronous servlets can trigger request and/or response mix-up between users. This issue affects Apache Tomcat: from 11.0.22 through 11.0.26, from 10.1.55 through 10.1.60, from 9.0.118 through 9.0.122. Users are recommended to upgrade to version 11.0.27, 10.1.61 or 9.0.123, which fixes the issue.
Product
Apache Tomcat
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record lists.apache.org openwall.com
Oct 19, 2026Summary Before version 0.9.0, Pingora accepted HTTP/2 requests whose Host header differed from the :authority pseudo-header.CVE-2026-105298 · Other software · Cloudflare · reported by cna@cloudflare.comMedium 6.3
Summary Before version 0.9.0, Pingora accepted HTTP/2 requests whose Host header differed from the :authority pseudo-header. Request filters, cache keys, and logs that read the request URI (session.req_header().uri) saw the :authority value, but the upstream received the client-supplied Host value. Pingora also accepted :authority values containing userinfo (for example, user@example.com). This violates RFC 9113 Section 8.3.1, which requires an intermediary to use the :authority value for Host and replace any existing Host field. Root cause * HTTP/2 to HTTP/1.1: Host was generated from :authority only when the request had no Host header, so a conflicting client Host was forwarded unchanged. * HTTP/2 to HTTP/2: the client Host header was removed and used to overwrite the upstream :authority, after request filters had already run against the original :authority. * The HTTP/2 server did not compare Host with :authority and did not reject userinfo in the authority. Impact A remote, unauthenticated attacker can send a single HTTP/2 request that the application sees as one host and the upstream receives as another. Where request filters, access contro
Product
https://github.com/cloudflare/pingora
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record github.com
Oct 19, 2026Summary Before version 0.8.1, Pingora's HTTP/2 server used the h2 crate's default limits unless the application set its own 16 MiB decoded header-list size aCVE-2026-105297 · Other software · Cloudflare · reported by cna@cloudflare.comHigh 7.5
Summary Before version 0.8.1, Pingora's HTTP/2 server used the h2 crate's default limits unless the application set its own 16 MiB decoded header-list size and no limit on concurrent streams. A remote, unauthenticated client can send 1-byte HPACK references to a near-empty header, making the server allocate hundreds of thousands of header fields per stream across an unlimited number of streams on one connection, and use HTTP/2 flow control to keep those streams open. This can exhaust memory and degrade or terminate the Pingora process. Impact Remote, unauthenticated denial of service against any Pingora service that terminates HTTP/2 (h2 or h2c) without explicitly setting max_header_list_size and max_concurrent_streams. The reporter showed that a single connection could get a Pingora process with a 2 GiB memory limit OOM-killed. Note that Cloudflare CDN customers were unaffected, as internal Pingora services at Cloudflare do not have HTTP/2 clients. Mitigation: * Upgrade to pingora 0.8.1 or later (fix: https://github.com/cloudflare/pingora/commit/d193c8d49b8b7c1c1ede93183759caa4f6906bbd ). When no H2Options are supplied, Pingora now advertises and enforces a
Product
https://github.com/cloudflare/pingora
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record github.com
Oct 14, 2026Uncontrolled Resource Consumption vulnerability in mtrudel bandit allows an unauthenticated remote attacker to pin HTTP/2 stream processes indefinitely via a trCVE-2026-105659 · Other software · mtrudel · reported by 6b3ad84c-e1a6-4bf7-a703-f496b71e49dbHigh 8.7
Uncontrolled Resource Consumption vulnerability in mtrudel bandit allows an unauthenticated remote attacker to pin HTTP/2 stream processes indefinitely via a trickle of small WINDOW_UPDATE frames. A stream whose response outruns the connection or stream send window blocks until the peer grants more window, and each block carries a 15 second deadline. Both deadlines restart whenever the peer makes partial progress. Bandit.HTTP2.Connection.finish_data/5 re-queues a partially advanced send in pending_sends with a fresh expires_at, so every WINDOW_UPDATE on stream 0, and every SETTINGS frame, resets the clock. Bandit.HTTP2.Stream.send_data/3 recurses on each stream WINDOW_UPDATE and re-arms a fresh after read_timeout. A peer that grants a few bytes every few seconds keeps the blocked stream process, its Plug state and any resource it holds mid-response alive for as long as it keeps dripping, and repeats this across streams and connections to exhaust server processes and memory. The two paths are independent. The stream-level block is reached on its own by widening the connection window with a large WINDOW_UPDATE on stream 0 and shrinking the per-stream window with a small SETTINGS_INI
Product
bandit
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record cna.erlef.org github.com
Oct 14, 2026During an upload, curl mishandles HTTP/2 `RST_STREAM` received from the server (with reason `HTTP_1_1_REQUIRED` or `REFUSED_STREAM`) leading to a use after freeCVE-2026-92392 · Other software · curl · reported by 2499f714-1537-4658-8207-48ae4bb9eae9High 8.1
During an upload, curl mishandles HTTP/2 `RST_STREAM` received from the server (with reason `HTTP_1_1_REQUIRED` or `REFUSED_STREAM`) leading to a use after free of a `struct Curl_easy` object.
Product
curl
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record curl.se curl.se
Oct 8, 2026HTTP/2 servers could end up crashing due to inadvertently modifying its HPACK encoder concurrently.CVE-2026-97032 · Other software · Go standard library · reported by security@golang.orgHigh 7.5
HTTP/2 servers could end up crashing due to inadvertently modifying its HPACK encoder concurrently. This happens because the server modifies the HPACK encoder from two goroutines without synchronization: one uses the encoder to encode a HEADERS frame as part of a response sent to a client and the other modifies the encoder's table size when handling a SETTINGS frame containing SETTINGS_HEADER_TABLE_SIZE that a client sends. A malicious client can repeatedly send a request while changing the header table size to crash the server.
Product
net/http
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record go.dev go.dev
Oct 8, 2026A malicious HTTP/2 peer can cause excessive CPU consumption in the client or server by opening a large number of streams and then sending many small SETTINGS frCVE-2026-78669 · Other software · Go standard library · reported by security@golang.orgHigh 7.5
A malicious HTTP/2 peer can cause excessive CPU consumption in the client or server by opening a large number of streams and then sending many small SETTINGS frames containing SETTINGS_INITIAL_WINDOW_SIZE values.
Product
net/http
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record go.dev go.dev
Oct 8, 2026The HTTP/2 server can refund connection-level flow control twice for the same data: Once when a client resets a stream (refunding data for any sent-but-unread pCVE-2026-78663 · Other software · Go standard library · reported by security@golang.orgCritical 9.1
The HTTP/2 server can refund connection-level flow control twice for the same data: Once when a client resets a stream (refunding data for any sent-but-unread portion of the stream), and again when a request handler reads the buffered data. A malicious client can exploit this to bypass the configured connection-level flow control limit (MaxReceiveBufferPerConnection). Total buffered data is still limited by the concurrent stream limit and stream-level flow control.
Product
net/http
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record go.dev go.dev
Oct 8, 2026Historically, we have been rather lax about malformed framing-related headers in our HTTP/2 implementation, as they cannot interfere with HTTP/2 framing.CVE-2026-78660 · Other software · Go standard library · reported by security@golang.orgHigh 7.5
Historically, we have been rather lax about malformed framing-related headers in our HTTP/2 implementation, as they cannot interfere with HTTP/2 framing. However, this makes it possible for our HTTP/2 implementation to forward responses containing such headers to an HTTP/1 client when acting as a reverse proxy. If the HTTP/1 client also does not behave strictly enough, this can result in response smuggling.
Product
net/http
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record go.dev go.dev
Sep 28, 2026Allocation of Resources Without Limits or Throttling vulnerability in elixir-mint mint allows a malicious HTTP/2 server to make the client hold up to about 16 MCVE-2026-92103 · Other software · elixir-mint · reported by 6b3ad84c-e1a6-4bf7-a703-f496b71e49dbMedium 6.3
Allocation of Resources Without Limits or Throttling vulnerability in elixir-mint mint allows a malicious HTTP/2 server to make the client hold up to about 16 MiB per connection in frames it should reject, consuming client memory. Mint.HTTP2.Frame.decode_next/2 in lib/mint/http2/frame.ex compares a frame with the client's max_frame_size (16,384 bytes by default) only once the whole declared payload has arrived. Until then it returns :more, and Mint.HTTP2 keeps every received byte in the connection buffer. A server can declare a frame length of up to 16,777,215 bytes and withhold the last byte, keeping roughly 1,024 times the advertised limit buffered for as long as the connection stays open. The server has to send every byte the client buffers, so there is no amplification, and the buffer stops at the 24-bit frame length limit. This issue affects mint: from 0.1.0 before 1.10.2.
Product
mint
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record cna.erlef.org github.com
Sep 28, 2026Allocation of Resources Without Limits or Throttling vulnerability in elixir-mint mint allows a malicious HTTP/2 server to exhaust memory on the client host andCVE-2026-91043 · Other software · elixir-mint · reported by 6b3ad84c-e1a6-4bf7-a703-f496b71e49dbHigh 8.2
Allocation of Resources Without Limits or Throttling vulnerability in elixir-mint mint allows a malicious HTTP/2 server to exhaust memory on the client host and cause a denial of service. Mint.HTTP2 enforces the client's max_header_list_size setting only on the compressed size of an inbound header block, while RFC 9113 section 6.5.2 defines the limit on the decoded header list. An HPACK indexed field costs one byte on the wire and decodes to a dynamic table entry of up to 4 KB, and join_cookie_headers/1 in lib/mint/http2.ex copies every cookie value of a response into one new binary. A header block under the default 256 KB wire limit therefore makes the client allocate about 1 GB for a single response, and several such responses in one delivery exhaust the memory of the process that owns the connection or of the whole VM. This issue affects mint: from 1.1.0 before 1.10.2.
Product
mint
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record cna.erlef.org github.com
Sep 23, 2026hpack is an HTTP/2 Header Encoding for Python.CVE-2026-59980 · Other software · python-hyper · reported by GitHubMedium 6.3
hpack is an HTTP/2 Header Encoding for Python. Prior to version 4.2.0, unbounded variable integer decoding can cause run-away computation on malformed input leading to O(n^2) runtime, effectively blocking further processing with large enough unsanitized input. A fix is available in python-hyper/hpack v4.2.0 to restricted variable integer decoding to uint32 to prevent run-away computation. As a workaround, sanitize input to hpack decoder for long sequences of `0xFF` values to prevent malicious use.
Product
hpack
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record cs.opensource.google docs.rs
Sep 23, 2026Inconsistent interpretation of HTTP/2 requests ('HTTP Request/Response smuggling') vulnerability in Apache Tomcat caused by a regression in fix for CVE-2026-412CVE-2026-86350 · Websites & servers · Apache Software Foundation · reported by security@apache.orgCritical 9.1
Inconsistent interpretation of HTTP/2 requests ('HTTP Request/Response smuggling') vulnerability in Apache Tomcat caused by a regression in fix for CVE-2026-41293 can trigger request header mix-up. This issue affects Apache Tomcat: from 11.0.22 through 11.0.25, from 10.1.55 through 10.1.59, from 9.0.118 through 9.0.121. Users are recommended to upgrade to version 11.0.26, 10.1.60 or 9.0.122, which fix the issue.
Product
Apache Tomcat
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record lists.apache.org
Sep 18, 2026A flaw was found in Netty's HTTP/2 stack.CVE-2026-93579 · Other software · Red Hat · reported by Red HatMedium 6.5
A flaw was found in Netty's HTTP/2 stack. This vulnerability allows a remote attacker to inject prohibited characters, such as NUL, Line Feed, and Carriage Return, into HTTP/2 header field values due to insufficient validation. When these values cross an HTTP/2 to HTTP/1.1 translation boundary, they can be exploited for request smuggling, header injection, or response splitting. This could lead to unauthorized access, data manipulation, or other security bypasses.
Product
Red Hat Build of Debezium 3.6
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record access.redhat.com access.redhat.com
Sep 18, 2026A flaw was found in Netty's HTTP/2 codec.CVE-2026-93567 · Other software · Red Hat · reported by Red HatHigh 7.5
A flaw was found in Netty's HTTP/2 codec. When converting HTTP/1 CONNECT requests to HTTP/2, the component incorrectly uses the Host header instead of the CONNECT authority-form request-target for the tunnel authority. A remote attacker can exploit this by supplying a different Host header, leading to a malformed HTTP/2 CONNECT request. This can bypass security controls such as tunnel allow-lists or egress policies, resulting in integrity loss.
Product
Red Hat Build of Apache Camel 3.33.3.SP2
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record access.redhat.com access.redhat.com
Sep 18, 2026A flaw was found in Netty's HTTP/2 HpackEncoder.CVE-2026-93492 · Other software · Red Hat · reported by Red HatMedium 5.3
A flaw was found in Netty's HTTP/2 HpackEncoder. A remote attacker can exploit this by sending HTTP/2 SETTINGS frames with a very large MAX_HEADER_TABLE_SIZE. This causes the HpackEncoder to store an excessive number of unique headers, leading to increased CPU usage and memory consumption, ultimately resulting in a Denial of Service (DoS).
Product
Red Hat Build of Debezium 3.6
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record access.redhat.com access.redhat.com
Sep 15, 2026libwebsockets HTTP/2 HPACK Path Header Parsing Out-Of-Bounds Write Remote Code Execution Vulnerability.CVE-2026-19773 · Other software · libwebsockets · reported by zdi-disclosures@trendmicro.comCritical 9.8
libwebsockets HTTP/2 HPACK Path Header Parsing Out-Of-Bounds Write Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of libwebsockets. Authentication is not required to exploit this vulnerability. The specific flaw exists within the parsing of HTTP/2 HPACK path header. The issue results from the lack of proper validation of user-supplied data, which can result in a write past the end of an allocated buffer. An attacker can leverage this vulnerability to execute code in the context of the current process. Was ZDI-CAN-31036.
Product
libwebsockets
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record github.com zerodayinitiative.com
Sep 8, 2026A client may issue HTTP/2 requests to a Jetty server that result in blocking writes that are never unblocked, eventually causing all threads to be blocked and tCVE-2026-12611 · Other software · Eclipse Foundation · reported by emo@eclipse.orgHigh 8.7
A client may issue HTTP/2 requests to a Jetty server that result in blocking writes that are never unblocked, eventually causing all threads to be blocked and the whole server to become unresponsive. This is caused by a race condition in the server when handling RST_STREAM frames and GOAWAY frames sent by the client. The race condition "resets" the HTTP2Flusher.terminated, previously set to a non-null value, to the null value, allowing entries to be enqueued in the flusher that however will never be processed. These unprocessed entries are the ones that would unblock the write-blocked threads.
Product
Eclipse Jetty
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record github.com
Sep 6, 2026A flaw in libcurl's handling of HTTP/2 Server Push streams, when the parent handle is set to share connections with other handles, can lead to use-after-free inCVE-2026-18924 · Other software · curl · reported by 2499f714-1537-4658-8207-48ae4bb9eae9Critical 9.1
A flaw in libcurl's handling of HTTP/2 Server Push streams, when the parent handle is set to share connections with other handles, can lead to use-after-free in the cleanup process.
Product
curl
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record curl.se curl.se
Aug 25, 2026Uncontrolled Resource Consumption vulnerability in Apache Tomcat via an allocation leak in the HTTP/2 backlog tracking when a stream is reset This issue affeCVE-2026-68763 · Websites & servers · Apache Software Foundation · reported by security@apache.orgHigh 7.5
Uncontrolled Resource Consumption vulnerability in Apache Tomcat via an allocation leak in the HTTP/2 backlog tracking when a stream is reset This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.24, from 10.1.0-M1 through 10.1.57, from 9.0.39 through 9.0.120. The following versions were EOL at the time the CVE was created but are known to be affected: from 8.5.59 through 8.5.100. Other unsupported versions may also be affected. Users are recommended to upgrade to version 11.0.25, 10.1.58 or 9.0.121, which fix the issue.
Product
Apache Tomcat
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record lists.apache.org openwall.com
Aug 13, 2026When a server is configured to support unencrypted HTTP/2, it reads a few bytes from each new connection to see if they contain the HTTP/2 client preface.CVE-2026-56853 · Other software · Go standard library · reported by security@golang.orgHigh 7.5
When a server is configured to support unencrypted HTTP/2, it reads a few bytes from each new connection to see if they contain the HTTP/2 client preface. ReadHeaderTimeout is unexpectedly not being applied when doing this.
Product
net/http
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record go.dev go.dev
Aug 6, 2026h2 is a pure-Python implementation of a HTTP/2 protocol stack.CVE-2026-71554 · Other software · python-hyper · reported by GitHubMedium 5.3
h2 is a pure-Python implementation of a HTTP/2 protocol stack. Versions up to and including 4.4.0 accept request header blocks containing more than one Host header, and forward every Host header to the consuming application. Where the consumer downgrades HTTP/2 to HTTP/1.1, the resulting request carries two Host header lines, providing a request smuggling primitive. This issue is fixed in version 4.4.1.
Product
h2
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record github.com github.com
Aug 4, 2026A flaw in Node.js HTTP/2 handling allows `nghttp2_session_mem_send()` to be called re-entrantly while `nghttp2_session_mem_recv()` is executing, resulting in a CVE-2026-56848 · Other software · nodejs · reported by support@hackerone.comHigh 7.5
A flaw in Node.js HTTP/2 handling allows `nghttp2_session_mem_send()` to be called re-entrantly while `nghttp2_session_mem_recv()` is executing, resulting in a heap-use-after-free. This vulnerability affects Node.js **26.x**, **24.x**, and **22.x**.
Product
node
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record nodejs.org
Aug 3, 2026A flaw in Node.js HTTP/2 handling can cause HTTP/2 retained header blocks evade maxSessionMemory and enable remote memory exhaustion.CVE-2026-56846 · Other software · nodejs · reported by support@hackerone.comHigh 7.5
A flaw in Node.js HTTP/2 handling can cause HTTP/2 retained header blocks evade maxSessionMemory and enable remote memory exhaustion. This vulnerability affects Node.js **24.x** and **22.x**.
Product
node
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record nodejs.org
Jul 29, 2026Apache Traffic Server updates the HTTP/2 HPACK dynamic table before confirming the header block encoded successfully, so an encode failure leaves the encoder ouCVE-2026-65100 · Websites & servers · Apache Software Foundation · reported by security@apache.orgMedium 6.3
Apache Traffic Server updates the HTTP/2 HPACK dynamic table before confirming the header block encoded successfully, so an encode failure leaves the encoder out of sync with the peer decoder and corrupts subsequent header blocks on the connection. This issue affects Apache Traffic Server: from 8.0.0 through 8.1.11, from 9.0.0 through 9.2.14, from 10.0.0 through 10.1.3. Users are recommended to upgrade to version 9.2.15 or 10.1.4, which fix the issue.
Product
Apache Traffic Server
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record lists.apache.org
Jul 29, 2026Apache Traffic Server reuses multiplexed HTTP/2 origin connections without verifying the server certificate covers the new request hostname.CVE-2026-65325 · Websites & servers · Apache Software Foundation · reported by security@apache.orgMedium 6.3
Apache Traffic Server reuses multiplexed HTTP/2 origin connections without verifying the server certificate covers the new request hostname. This issue affects Apache Traffic Server: from 9.0.0 through 9.2.14, from 10.0.0 through 10.1.3. Users are recommended to upgrade to version 9.2.15 or 10.1.4, which fix the issue.
Product
Apache Traffic Server
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record lists.apache.org
Jul 29, 2026Apache Traffic Server drops the per-stream buffer cap when dechunking HTTP/2 or HTTP/3 responses, letting a slow client exhaust server memory.CVE-2026-65324 · Websites & servers · Apache Software Foundation · reported by security@apache.orgHigh 8.2
Apache Traffic Server drops the per-stream buffer cap when dechunking HTTP/2 or HTTP/3 responses, letting a slow client exhaust server memory. This issue affects Apache Traffic Server: from 8.0.0 through 8.1.11, from 9.0.0 through 9.2.14, from 10.0.0 through 10.1.3. Users are recommended to upgrade to version 9.2.15 or 10.1.4, which fix the issue.
Product
Apache Traffic Server
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record lists.apache.org
Jul 29, 2026Apache Traffic Server forwards HTTP/2 origin trailers to HTTP/1 clients without proper chunked framing when converting HTTP/2 to HTTP/1.CVE-2026-58153 · Websites & servers · Apache Software Foundation · reported by security@apache.orgMedium 6.3
Apache Traffic Server forwards HTTP/2 origin trailers to HTTP/1 clients without proper chunked framing when converting HTTP/2 to HTTP/1. This issue affects Apache Traffic Server: from 10.0.0 through 10.1.3. Users are recommended to upgrade to version 9.2.15 or 10.1.4, which fix the issue.
Product
Apache Traffic Server
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record lists.apache.org
Jul 29, 2026Apache Traffic Server can be crashed or driven to resource exhaustion by abusive HTTP/2 framing and flow-control.CVE-2026-58151 · Websites & servers · Apache Software Foundation · reported by security@apache.orgHigh 8.7
Apache Traffic Server can be crashed or driven to resource exhaustion by abusive HTTP/2 framing and flow-control. This issue affects Apache Traffic Server: from 8.0.0 through 8.1.11, from 9.0.0 through 9.2.14, from 10.0.0 through 10.1.3. Users are recommended to upgrade to version 9.2.15 or 10.1.4, which fix the issue.
Product
Apache Traffic Server
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record lists.apache.org
Jul 29, 2026Apache Traffic Server does not reject Transfer-Encoding in HTTP/2 requests, allowing downgrade request smuggling.CVE-2026-58150 · Websites & servers · Apache Software Foundation · reported by security@apache.orgHigh 7.8
Apache Traffic Server does not reject Transfer-Encoding in HTTP/2 requests, allowing downgrade request smuggling. This issue affects Apache Traffic Server: from 8.0.0 through 8.1.11, from 9.0.0 through 9.2.14, from 10.0.0 through 10.1.3. Users are recommended to upgrade to version 9.2.15 or 10.1.4, which fix the issue.
Product
Apache Traffic Server
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record lists.apache.org
Jul 28, 2026Allocation of resources without limits vulnerability in ninenines cowlib allows an unauthenticated remote HTTP/2 or HTTP/3 peer to exhaust memory on the vulneraCVE-2026-59248 · Other software · ninenines · reported by 6b3ad84c-e1a6-4bf7-a703-f496b71e49dbHigh 8.7
Allocation of resources without limits vulnerability in ninenines cowlib allows an unauthenticated remote HTTP/2 or HTTP/3 peer to exhaust memory on the vulnerable server (or client) and cause a denial of service. The HPACK and QPACK prefixed-integer decoder cow_hpack_common:dec_big_int/3 in src/cow_hpack_common.hrl (invoked from cow_hpack:decode/2 in src/cow_hpack.erl and from cow_qpack:decode_field_section/3 in src/cow_qpack.erl) reads continuation octets until it sees one whose high bit is clear, evaluating Int + (Value bsl M) at each step with the shift M growing by seven per octet. No limit is enforced on the number of continuation octets, on the resulting bit width, or on the value; the decoder consumes whatever encoded length the peer supplies. Because Erlang integers are immutable, each intermediate Value bsl M and each accumulator update allocates a fresh bignum whose digit width grows linearly with the number of octets processed so far. Summed across the whole decode, the transient bignum digit materialization is on the order of the square of the encoded length. A single maximal HPACK indexed representation carried inside one HTTP/2 HEADERS plus one CONTINUATION frame a
Product
cowlib
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record cna.erlef.org github.com
Jul 23, 2026SwiftNIO HTTP/2 was missing validation on inbound HEADERS frames that let CR, LF, NUL, SP and other control characters reach an HTTP/1.1 backend through NIOHTTPCVE-2026-64785 · Computers, phones & browsers · Apple · reported by product-security@apple.comMedium 5.3
SwiftNIO HTTP/2 was missing validation on inbound HEADERS frames that let CR, LF, NUL, SP and other control characters reach an HTTP/1.1 backend through NIOHTTP2's HTTP/2-to-HTTP/1 codec, enabling HTTP request smuggling or response splitting. This vulnerability is addressed in swift-nio-http2 version 1.45.0.
Product
swift-nio-http2
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record github.com
Jul 16, 2026h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3.CVE-2026-54340 · Other software · h2o · reported by GitHubHigh 7.5
h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3. Prior to commit 9265bdd, there is an HTTP/2 state amplification issue that combines HPACK decompression amplification with Slowloris-style stream stalling. Amplified decoded header state can be retained by stalled HTTP/2 streams, and depending on the configuration, additional limits are needed to bound decoded header state and prevent attack. This issue has been fixed by commit 9265bdd.
Product
h2o
What to do
Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD record github.com github.com

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.

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