CVE-2026-81010 io_uring/waitid: honor task_work cancellation
A race condition in the Linux kernel io_uring waitid handler allows incorrect task context execution, potentially leading to undefined behavior or crashes.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-81010?
CVE-2026-81010 is a high-severity vulnerability in Linux, published on 11 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
io_uring/waitid: honor task_work cancellation
io_waitid_cb() may run through the fallback task_work path when task_work_add() can no longer queue work to the originating task. The fallback runs from a kworker and io_uring marks such task work as canceled through tw.cancel.
io_waitid_cb() currently ignores tw.cancel and calls __do_wait(). waitid is task-context dependent: __do_wait() performs child lookup relative to current, and the retry path also uses current->signal->wait_chldexit. If the callback runs from the fallback kworker, current is therefore not the task that submitted the request.
Honor tw.cancel before entering __do_wait(). Complete the request with -ECANCELED and skip the siginfo copy, since canceled task work may run without the submitting task's userspace execution context.
Keep the existing siginfo handling for normal waitid completion and explicit cancellation.
Which versions are affected by CVE-2026-81010?
How do I fix CVE-2026-81010?
Apply the vendor's patch.
Is CVE-2026-81010 being exploited?
There is no known exploitation of CVE-2026-81010 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-81010, DEBIAN-CVE-2026-81010, GHSA-qqff-gjp9-r6f6, UBUNTU-CVE-2026-81010.