CVE-2026-74753 perf: Reject exited events as group leaders
A use-after-free vulnerability in the Linux kernel perf subsystem allows attackers to execute arbitrary code or escalate privileges via crafted event groups.
- 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-2026-74753?
CVE-2026-74753 is a high-severity use after free vulnerability in Linux, published on 26 Aug 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:
perf: Reject exited events as group leaders
perf_event_remove_on_exec() sets remove-on-exec events to the EXIT state and detaches their group relationships. The event's file descriptor can remain open, however, and perf_event_open() currently accepts that event as a group leader because its early validation rejects only REVOKED and DEAD events.
A new sibling can consequently be linked to the detached leader. When the leader is closed, perf_group_detach() observes that its PERF_ATTACH_GROUP bit is already clear and skips the new sibling. The sibling then retains a group_leader pointer to the freed event.
Reject group leaders in the EXIT state. Perform the check while holding the shared context mutex so that an exec in the target task cannot detach the leader between validation and group attachment.
[peterz: make the earlier test fully consistent]
Which versions are affected by CVE-2026-74753?
How do I fix CVE-2026-74753?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-74753 being exploited?
There is no known exploitation of CVE-2026-74753 in the wild and no public exploit code.
Sources
Also known as AZL-97778, BELL-CVE-2026-74753, DEBIAN-CVE-2026-74753, GHSA-4mpw-g9mg-jrm7, UBUNTU-CVE-2026-74753.