CVE-2026-80572 Input: byd - synchronize timer deletion before freeing private data
A race condition in the Linux kernel BYD input driver allows use-after-free, potentially enabling local attackers to execute code or escalate privileges.
- 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-2026-80572?
CVE-2026-80572 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:
Input: byd - synchronize timer deletion before freeing private data
byd_disconnect() uses timer_delete() before freeing the driver's private data. This does not wait for a running byd_clear_touch() callback, which dereferences the private data and its psmouse pointer. A callback racing with disconnect can therefore access the private data after it has been freed. The timer can also still be re-armed by byd_process_byte() while the disconnect is in progress.
Use timer_shutdown_sync() before freeing the private data: it waits for a running callback and turns any later re-arm attempt into a no-op.
Which versions are affected by CVE-2026-80572?
How do I fix CVE-2026-80572?
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-2026-80572 being exploited?
There is no known exploitation of CVE-2026-80572 in the wild and no public exploit code.
Sources
Also known as AZL-97769, BELL-CVE-2026-80572, DEBIAN-CVE-2026-80572, GHSA-g6j6-j6hv-j2v2, UBUNTU-CVE-2026-80572.