Copy Fail: Linux Kernel Flaw Grants Root Access On All Major Distributions

[beyondmachines1@infosec.exchange]

Copy Fail: Linux Kernel Flaw Grants Root Access On All Major Distributions

A Linux kernel vulnerability called "Copy Fail" (CVE-2026-31431) allows unprivileged local users to gain root privileges with 100% reliability by corrupting the shared page cache. The flaw affects nearly all Linux distributions since 2017 and enables container escapes because the memory corruption does not modify files on disk.

**If you run Linux servers, especially shared environments like Kubernetes clusters, CI/CD runners, or multi-tenant hosts, patch your kernel immediately to a version that includes the fix (mainline commit a664bf3d603d) for CVE-2026-31431. If you can't patch right away, disable the vulnerable module by running echo "install algif_aead /bin/false" > /etc/modprobe.d/disable-algif.conf followed by rmmod algif_aead, and for untrusted code environments block AF_ALG socket creation via seccomp as a long-term safeguard.**
#cybersecurity #infosec #advisory #vulnerability
https://beyondmachines.net/event_details/copy-fail-linux-kernel-flaw-grants-root-access-on-all-major-distributions-w-l-v-0-c/gD2P6Ple2L