cbcvebase.
CVE-2026-31431
published 2026-04-22

CVE-2026-31431: In the Linux kernel, the following vulnerability has been resolved: crypto: algif_aead - Revert to operating out-of-place This mostly reverts commit…

PriorityP189high7.8CVSS 3.1
AVLACLPRLUINSUCHIHAH
KEVITWEXPLOITInitial access
CISA Known Exploited Vulnerabilitydue 2026-05-15
Exploited in the wild
EPSS
94.55%
99.8th percentile
In the Linux kernel, the following vulnerability has been resolved: crypto: algif_aead - Revert to operating out-of-place This mostly reverts commit 72548b093ee3 except for the copying of the associated data. There is no benefit in operating in-place in algif_aead since the source and destination come from different mappings. Get rid of all the complexity added for in-place operation and just copy the AD directly.

Affected

250 ranges· showing 25
VendorProductVersion rangeFixed in
aristacloudvision_agni2024.4.0 – 2025.2.2
aristacloudvision_portal2024.2.0 – 2026.1.0
aristanetvisor_os< 7.1.07.1.0
aristanetvisor_os
aristanetvisor_os
aristavelocloud_edge4.5.0 – 6.4.1
canonicalubuntu_linux
canonicalubuntu_linux
canonicalubuntu_linux
canonicalubuntu_linux
canonicalubuntu_linux
canonicalubuntu_linux
canonicalubuntu_linux
debiandebian_linux
debiandebian_linux
debiandebian_linux
github.comsiderolabs_talos>= 0 < 1.12.71.12.7
linuxlinux
linuxlinux>= 72548b093ee38a6d4f2a19e6ef1948ae05c181f7 < 893d22e0135fa394db81df88697fba6032747667893d22e0135fa394db81df88697fba6032747667
linuxlinux>= 72548b093ee38a6d4f2a19e6ef1948ae05c181f7 < 19d43105a97be0810edbda875f2cd03f30dc130c19d43105a97be0810edbda875f2cd03f30dc130c
linuxlinux>= 72548b093ee38a6d4f2a19e6ef1948ae05c181f7 < 961cfa271a918ad4ae452420e7c303149002875b961cfa271a918ad4ae452420e7c303149002875b
linuxlinux>= 72548b093ee38a6d4f2a19e6ef1948ae05c181f7 < 3115af9644c342b356f3f07a4dd1c8905cd9a6fc3115af9644c342b356f3f07a4dd1c8905cd9a6fc
linuxlinux>= 72548b093ee38a6d4f2a19e6ef1948ae05c181f7 < 8b88d99341f139e23bdeb1027a2a3ae10d341d828b88d99341f139e23bdeb1027a2a3ae10d341d82
linuxlinux>= 72548b093ee38a6d4f2a19e6ef1948ae05c181f7 < fafe0fa2995a0f7073c1c358d7d3145bcc9aedd8fafe0fa2995a0f7073c1c358d7d3145bcc9aedd8
linuxlinux>= 72548b093ee38a6d4f2a19e6ef1948ae05c181f7 < ce42ee423e58dffa5ec03524054c9d8bfd4f6237ce42ee423e58dffa5ec03524054c9d8bfd4f6237

Detection & IOCsextracted from sources · hover to see the quote

commandecho "install algif_aead /bin/false" > /etc/modprobe.d/disable-algif.conf rmmod algif_aead
  • Detect exploitation attempts by monitoring for unexpected privilege escalation to UID 0 from low-privilege processes, particularly those using only standard system calls (no unusual syscalls or memory tricks).
  • Monitor integrity of setuid-root binaries (e.g., /usr/bin/su) in the page cache at runtime; unexpected modification without corresponding disk changes is a strong indicator of exploitation.
  • Hunt for Go and Rust implementations of the Copy Fail exploit in open-source repositories and on endpoints, as these variants have already been observed in the wild.
  • The exploit performs a controlled 4-byte overwrite in the kernel page cache — look for anomalous kernel page cache behavior or use of kernel integrity monitoring tools to flag in-memory binary corruption.
  • The PoC is a 732-byte Python script; scan endpoints and CI/CD environments for small Python scripts invoking AF_ALG sockets and splice() as an indicator of exploit staging.
  • ·The vulnerability only affects Linux kernels with the algif_aead module loaded; disabling it blocks exploitation but may break applications using the AF_ALG AEAD interface.
  • ·The vulnerability is not remotely exploitable in isolation; it requires a local foothold (e.g., SSH access, malicious CI job, or container escape) to be leveraged.
  • ·Container environments (Docker, LXC, Kubernetes) are at elevated risk because they grant access to the AF_ALG subsystem by default when algif_aead is loaded on the host kernel, enabling container escape.
  • ·Fixed kernel versions are 6.18.22, 6.19.12, and 7.0; some distributions (e.g., Fedora 42+) have updates but no official CVE advisory, so version checks alone may be insufficient to confirm patch status.
  • ·The exploit is architecture-aware and targets both AMD64 and AARCH64; detection and mitigation strategies must account for both architectures.

CVSS provenance

nvdv3.17.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
ghsa7.8HIGH
vulncheck7.8HIGH
cisa7.8HIGH
vendor_ubuntu7.8HIGH
vendor_redhat5.5MEDIUM
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