CVE-2026-89899 media: cec: disable delayed work before freeing an interrupted transmit
A race condition in the Linux kernel CEC driver allows freeing memory while delayed work is pending, potentially leading to use-after-free and system 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-2026-89899?
CVE-2026-89899 is a high-severity use after free vulnerability in Linux, published on 16 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:
media: cec: disable delayed work before freeing an interrupted transmit
cec_transmit_msg_fh() drops adap->lock to wait for a blocking transmit in wait_for_completion_killable(). If that wait is interrupted by a signal, cancel_delayed_work_sync() can run before the CEC kthread arms the reply timeout via schedule_delayed_work(&data->work) in cec_transmit_done_ts(). The work is then armed after the cancel, and the data is freed with its delayed_work still pending:
ODEBUG: free active (active state 0) object: ... hint: cec_wait_timeout
Use disable_delayed_work_sync(): it cancels the work and disables it, so the later schedule_delayed_work() becomes a no-op and the work cannot be re-armed. The data is freed right after, so it need not be re-enabled.
Which versions are affected by CVE-2026-89899?
How do I fix CVE-2026-89899?
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-2026-89899 being exploited?
There is no known exploitation of CVE-2026-89899 in the wild and no public exploit code.
Sources
Also known as AZL-101241, BELL-CVE-2026-89899, DEBIAN-CVE-2026-89899, GHSA-2c95-6v37-x3vh, UBUNTU-CVE-2026-89899.