CVE-2026-80749

CVE-2026-80749 is an out-of-bounds memory read in the Linux kernel's DRM connector HDMI code: a helper function copies a 28-byte HDMI audio infoframe into the connector's generic destination buffer but uses the destination's 60-byte size, reading roughly 32 bytes past the end of the source allocation. It is triggered locally when an affected DRM driver copies an audio infoframe during HDMI connector operation; the flaw was actually discovered by kernel developers running KUnit tests under KASAN while debugging unrelated code. Because the bug only reads and never writes memory, it cannot corrupt kernel data, but an overread could cross the end of a page and cause a page fault ('accvio'), potentially crashing the system; the 7.1 High CVSS score (AV:L/AC:L/PR:L/UI:N, high confidentiality and availability impact) reflects the local attack vector, though the kernel maintainer states real-world impact is unlikely. Any Linux system running a kernel containing the flawed DRM HDMI connector helper is affected, although the advisory lists no specific affected or fixed kernel versions. No public proof-of-concept or in-the-wild exploitation is known, and EPSS assigns roughly a 0.2% probability of exploitation within 30 days (5th percentile).

What to do: Watch your distribution or vendor kernel advisory for the drm/connector/hdmi fix and update when a patched kernel is offered; the advisory provides no fixed version number, so rely on vendor backport notes. Relevance can be gauged by whether your system's graphics driver uses the kernel's HDMI connector framework (HDMI audio path). Impact is limited to a local, read-only overread that could at worst cross a page boundary and cause a crash, so patch at normal cadence rather than urgently; no mitigations or workarounds are described.