CVE-2026-63855 drm/amdgpu/vcn: set no_user_fence for VCN v2.5 enc/dec rings
The Linux kernel AMD GPU driver fails to reject unsupported user fence submissions, potentially causing system instability or 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-2026-63855?
CVE-2026-63855 is a high-severity vulnerability in Linux kernel, published on 19 Jul 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:
drm/amdgpu/vcn: set no_user_fence for VCN v2.5 enc/dec rings
VCN encoder and decoder rings do not support 64-bit user fence writes, reject CS submissions with user fences.
(cherry picked from commit efc9dd5590894109bce9a0bfe1fa5592dd6b20b1)
Weakness: CWE-20
Which versions are affected by CVE-2026-63855?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-63855?
Apply the vendor's patch.
Is CVE-2026-63855 being exploited?
There is no known exploitation of CVE-2026-63855 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-63855, DEBIAN-CVE-2026-63855, GHSA-rjvx-mc7h-2h7x, ROOT-OS-DEBIAN-11-CVE-2026-63855, ROOT-OS-DEBIAN-12-CVE-2026-63855, ROOT-OS-UBUNTU-2204-CVE-2026-63855 and 1 more.