CVE-2026-64544: In the Linux kernel, the following vulnerability has been resolved: crypto: asymmetric_keys - fix OOB read in pefile_digest_pe_contents pefile_digest_pe

In the Linux kernel, the following vulnerability has been resolved: crypto: asymmetric_keys - fix OOB read in pefile_digest_pe_contents pefile_digest_pe_conte

In the Linux kernel, the following vulnerability has been resolved: crypto: asymmetric_keys - fix OOB read in pefile_digest_pe_contents pefile_digest_pe_contents() computes the trailing-data hash length as pelen - (hashed_bytes + certs_size). A crafted PE can make the addition exceed pelen, causing the unsigned subtraction to underflow to ~4 GiB. This is passed to crypto_shash_update() which reads out of bounds and panics on unmapped vmalloc guard pages. BUG: unable to handle page fault for address: ffffc900038d8000 Oops: Oops: 0000 [#1] SMP KASAN NOPTI RIP: 0010:sha256_blocks_generic (lib/crypto/sha256.c:152) Call Trace: <TASK> __sha256_update (lib/crypto/sha256.c:208) crypto_sha256_update (crypto/sha256.c:142) verify_pefile_signature (crypto/asymmetric_keys/verify_pefile.c:436) kexec_kernel_verify_pe_sig (kernel/kexec_file.c:151) __do_sys_kexec_file_load (kernel/kexec_file.c:406) do_syscall_64 (arch/x86/entry/syscall_64.c:94) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121) </TASK> Kernel panic - not syncing: Fatal exception Validate that the addition does not overflow and the result does not exceed pelen before the subtraction. Return -EL

Description from the National Vulnerability Database, published by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

What it means for a small business

Linux is on the computers, phones or browsers your team uses every day. Turn on automatic updates and restart: most of these fixes only take effect after a restart.

How likely is an attack? The Exploit Prediction Scoring System, run by FIRST (the global association of security response teams), puts the odds of this one being exploited in the next 30 days at 0.18%, higher than 7% of CVEs. That’s low, but low isn’t zero, and the odds jump the day someone publishes an exploit. Scored October 29, 2026, updated daily.

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Sources

Part of the Huttenlocher Technologies vulnerability database, refreshed twice a day from CISA and the NVD. The title, category and plain-language guidance are ours; check the linked record before acting on a detail. This is general guidance, not a review of your systems.

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