CVE-2026-78118 Linux Kernel - Use After Free

The kernel helper z_waitq_head() in kernel/include/wait_q.h contains a use-after-free and out-of-bounds write caused by improper locking on SMP systems in kernel/timer.c, letting unprivileged local attackers cause kernel crashes or state corruption, exploit requires multi-CPU system and local code execution with precise timing.

CVSS base score 7.0 /10
High
CISA KEV
Not listed
Public exploit
None known
Authentication
Required
View the NVD record ↗

Details

Type
Use After Free
Impact
Denial Of Service
CVSS vector
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Published
21 October 2026
Updated
22 October 2026
Weakness
CWE-362

Vendor fix

Update to the latest kernel version with the fix that adds proper locking in z_waitq_head and timer expiration handler.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

References

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