CVE-2026-89893 media: cx23885: cancel NetUP CI work before teardown
A use-after-free vulnerability in the Linux kernel cx23885 driver allows attackers to cause denial of service or execute code via race conditions during device teardown.
- 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-2026-89893?
CVE-2026-89893 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: cx23885: cancel NetUP CI work before teardown
netup_ci_exit() frees a netup_ci_state while its work item, netup_read_ci_status(), may still be pending or running on the system workqueue. The worker obtains the state with container_of() and dereferences it, so it must not outlive the state.
netup_ci_init() queues the initial status read, and CI GPIO interrupts subsequently queue the same work from netup_ci_slot_status(). During remove, cx23885_finidev() calls free_irq() before the CI device is unregistered. free_irq() prevents further IRQ handlers from running, but does not drain work queued previously, so the worker can run after netup_ci_exit() frees the state.
Call cancel_work_sync() before dvb_ca_en50221_release() and kfree().
This issue was found by an in-house static analysis tool.
Which versions are affected by CVE-2026-89893?
How do I fix CVE-2026-89893?
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-2026-89893 being exploited?
There is no known exploitation of CVE-2026-89893 in the wild and no public exploit code.
Sources
Also known as AZL-101516, BELL-CVE-2026-89893, DEBIAN-CVE-2026-89893, GHSA-8263-vr49-mgcg, UBUNTU-CVE-2026-89893.