CVE-2026-89818

A flaw was found in the Linux kernel's drm/amdgpu/vcn component. An integer overflow vulnerability exists in the dec_msg buffer count check. A local attacker could exploit this by providing a specially crafted message, causing the buffer count expression to wrap around. This allows the parser to read or write beyond the intended buffer boundaries, potentially leading to memory corruption and a denial of service.

This vulnerability is rated Moderate severity rather than Important because successful exploitation requires local user privileges, access to the AMDGPU device node, and hardware equipped with Video Core Next (VCN) support. Furthermore, triggering the condition requires uncommon prerequisites, including creating multi-gigabyte buffer allocations to bypass earlier validation steps. In typical enterprise server deployments that lack AMD GPU hardware or run as virtual machines without graphics passthrough, the relevant kernel routines are never invoked.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.