CVE-2026-97986 virtio_input: stop callbacks before unregistering input device
A race condition in the Linux kernel virtio_input driver allows use-after-free, potentially leading to code execution or denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-97986?
CVE-2026-97986 is an use after free vulnerability in Linux, published on 25 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:
virtio_input: stop callbacks before unregistering input device
virtinput_remove() unregisters the input device before resetting the virtio device. virtinput_recv_events() drops vi->lock around input_event(), so clearing vi->ready does not stop a callback that passed the entry check. It can still use vi->idev, requeue buffers and kick the queue.
Reset first, as virtinput_freeze() already does. With the preceding core change, reset waits for callbacks before input_unregister_device() can free vi->idev. Recheck vi->ready after taking the lock again: keep draining completed events so an input packet is not truncated, but stop requeueing buffers and kicking the queue.
With evdev attached, input_unregister_handle() currently waits for an RCU grace period, which also waits out IRQ callbacks. This masks the lifetime bug on PCI and MMIO, but does not protect sleepable callbacks on other transports.
Which versions are affected by CVE-2026-97986?
How do I fix CVE-2026-97986?
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-2026-97986 being exploited?
There is no known exploitation of CVE-2026-97986 in the wild and no public exploit code.
Sources
Also known as AZL-104862, BELL-CVE-2026-97986, DEBIAN-CVE-2026-97986, GHSA-5v98-rq5r-8rxh, UBUNTU-CVE-2026-97986.