A flaw in the Linux kernel’s AMDGPU VCN v5.0.0 encoder ring prevents command submissions when 64‑bit user fence values are written. The kernel rejects the CS requests, causing encoded or decoded video operations to fail and leading to service interruption for applications that rely on GPU video acceleration. The weakness is reflected in CWE‑1287, signifying improper handling of user data that results in denial of functionality.

The vulnerability affects Linux systems whose kernels include the AMDGPU VCN v5.0.0 ring implementation. No specific kernel release numbers are listed in the data, so any distribution or custom kernel that still contains the unpatched VCN ring logic is potentially impacted. Users of AMD GPUs that rely on VCN hardware acceleration for encode or decode operations may experience this issue.

The CVSS score of 7.8 indicates high severity, yet the EPSS score is below 1% and the flaw is not listed in CISA’s KEV catalog, suggesting a low likelihood of active exploitation. The bug is contained within the kernel’s handling of VCN user fences, so an attacker would need local kernel execution or privileged access to trigger it. The issue has already been patched upstream in commit 49b1fbbb5a071197ee71e2d70959b1cb29bdc317, which disables the no_user_fence requirement for VCN v5.0.0 rings.