CVE-2026-23106: Linux Kernel

Medium severity, CVSS 5.5. EPSS: 0.1% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: timekeeping: Adjust the leap state for the correct auxiliary timekeeper When __do_ajdtimex() was introduced to handle adjtimex for any timekeeper, this reference to tk_core was not updated. When called on an auxiliary timekeeper, the core timekeeper would be updated incorrectly. This gets caught by the lock debugging diagnostics because the timekeepers sequence lock gets written to without holding its associated spinlock: WARNING: include/linux/seqlock.h:226 at __do_adjtimex+0x394/0x3b0, CPU#2: test/125 aux_clock_adj (kernel/time/timekeeping.c:2979) __do_sys_clock_adjtime (kernel/time/posix-timers.c:1161 kernel/time/posix-timers.c:1173) do_syscall_64 (arch/x86/entry/syscall_64.c:63 (discriminator 1) arch/x86/entry/syscall_64.c:94 (discriminator 1)) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:131) Update the correct auxiliary timekeeper.

Affected products

• Linux Linux Kernel: from 6.17, before 6.18.8 (fixed in 6.18.8); version 6.19 only

Published 2026-02-04. Last modified 2026-06-17.