CVE-2026-98260

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

exec: Cleanup POSIX timers right after de_thread()

A per-thread CPU timer holds a reference to the PID of the thread it is

attached to and, while it is armed, its node is queued in that thread's

posix_cputimers. The task is looked up by that PID.

When a non-leader thread exec()s, de_thread() changes which task owns

that PID. pid_task(timer->it.cpu.pid, PIDTYPE_PID) then returns NULL,

but the node is still queued on tsk, which is alive. timer_lock_sighand()

takes a failed lookup to mean that the node is already dequeued, so it

has nothing to undo.

begin_new_exec() calls posix_cpu_timers_exit(me) right after

exec_task_namespaces() and that removes the leftover node, so the state

normally stays invisible. But bprm->point_of_no_return is set before

de_thread(), so if unshare_files(), set_mm_exe_file(), exec_mmap() or

exec_task_namespaces() fails, the task dies before it gets there.

exit_itimers() then frees the k_itime

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References