CVE-2026-31431. 100% Reliable Linux LPE — no race, no per-distro offsets, page-cache write that bypasses on-disk file-integrity tools and crosses containers. Found by Xint Code.
It looks like the fixes were merged in 6.18, 6.19, and 7.0. But all older (but supported) LTS kernels didn’t have the fix, like 6.12, which is used in Debian 13. And it also seems that Ubuntu, RHEL, and SUSE had not picked up the patches in their kernel versions.
What I read said the patch was merged into main on April 1st, so they should have.
It looks like the fixes were merged in 6.18, 6.19, and 7.0. But all older (but supported) LTS kernels didn’t have the fix, like 6.12, which is used in Debian 13. And it also seems that Ubuntu, RHEL, and SUSE had not picked up the patches in their kernel versions.
The kernel 6.12.73-1 used by Debian Trixie is still vulnerable. Applying security updates should update the kernel to 6.12.85-1 and fix the issue.
https://security-tracker.debian.org/tracker/CVE-2026-31431
Edit: Kernel 6.1.170-1 just got released and fixes the vulnerability.
This thread gives a good rundown of what happened: https://infosec.exchange/@wdormann/116489443704631952