CVE-2026-80777 futex/pi: Plug private futex exec() race
A race condition in the Linux kernel futex implementation allows local attackers to exploit a memory management gap during exec() to potentially escalate privileges or execute code.
- 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-2026-80777?
CVE-2026-80777 is a vulnerability in Linux, published on 4 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:
futex/pi: Plug private futex exec() race
The check for private futexes whether the waiter's mm, which is stored in the futex_key and copied into the pi_state, is the same as the owner's mm is not sufficient for exec(). exec() has a gap where the mm check fails to give the correct answer:
exec() ... exec_release_mm() futex_exec_release() tsk::futex::exit_state = EXITING; cleanup_robust_list(); 1) tsk::futex::exit_state = OK; ... old_mm = tsk::mm; 2) tsk::mm = ->mm;
Between #1 and #2 the check for the mm is wrong as that mm is about to be swapped out and eventually freed.
Plug this gap by:
1) Setting tsk::futex::exit_state to FUTEX_STATE_DEAD in futex_exec_release()
2) Setting tsk::futex::exit_state to FUTEX_STATE_OK after the mm has been switched.
From a futex point of view the task is dead after it finished the robust list cleanup up to the point where it sets the state to OK again.
Which versions are affected by CVE-2026-80777?
How do I fix CVE-2026-80777?
Apply the vendor's patch.
Is CVE-2026-80777 being exploited?
There is no known exploitation of CVE-2026-80777 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-80777, DEBIAN-CVE-2026-80777, GHSA-7pm4-4mcq-p2r3, UBUNTU-CVE-2026-80777.