CVE-2026-23039 drm/gud: fix NULL fb and crtc dereferences on USB disconnect
A local attacker with physical access can cause a kernel crash by disconnecting a USB display, leading to denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-23039?
CVE-2026-23039 is a vulnerability in Linux, published on 31 Jan 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
In the Linux kernel, the following vulnerability has been resolved:
drm/gud: fix NULL fb and crtc dereferences on USB disconnect
On disconnect drm_atomic_helper_disable_all() is called which sets both the fb and crtc for a plane to NULL before invoking a commit.
This causes a kernel oops on every display disconnect.
Add guards for those dereferences.
Which versions are affected by CVE-2026-23039?
How do I fix CVE-2026-23039?
Apply the vendor's patch.
Is CVE-2026-23039 being exploited?
There is no known exploitation of CVE-2026-23039 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-23039, DEBIAN-CVE-2026-23039, GHSA-8v58-m3wh-hhg4, UBUNTU-CVE-2026-23039.