The Linux kernel’s DRM/AMDGPU VCN driver contains a flaw where the VCN v2.5 encoder and decoder rings do not support 64‑bit user fence writes and consequently reject any command stream containing such fences. When a command packet with a 64‑bit user fence is submitted, the driver refuses the packet and the associated GPU work fails. This driver‑level defect is classified as CWE‑1287 and results only in a denial‑of‑service impact for applications that rely on VCN‑based video or GPU workloads; no confidentiality or integrity compromise is indicated in the description.

All Linux kernel builds that include the generic AMDGPU VCN driver before the inclusion of commit efc9dd5590894109bce9a0bfe1fa5592dd6b20b1 are potentially affected. This encompasses any distro kernel that has not yet merged the patch and uses VCN v2.5 rings. Kernels produced after the commit are considered safe.

The CVSS base score of 7.8 signals a serious denial‑of‑service risk, while the EPSS score of less than 1 % indicates a very low likelihood of exploitation. The vulnerability is not listed in the CISA KEV catalog. Based on the description, the attack likely requires local or privileged access that allows an attacker to craft DRM command packets containing a 64‑bit user fence, leading to GPU work rejection but no privilege escalation or code execution.