CVE-2026-80749 drm/connector/hdmi: Fix out of bounds memory read
An out-of-bounds memory read in the Linux kernel's HDMI connector code can cause a system crash, requiring a kernel patch.
- 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-2026-80749?
CVE-2026-80749 is a high-severity memory corruption vulnerability in Linux, published on 3 Sep 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/connector/hdmi: Fix out of bounds memory read
A helper function was copying a given audio infoframe into the connector's copy but using the size of the destination (a generic target, sized to accept many different data blocks) not the source (a very specific type of data block). Thus, it was copying 60 bytes of data from a 28 byte allocation.
Fix that by using the source size instead, together with a build bug on the source size actually being smaller than the destination.
I hit this running KUnit tests under KASAN (while debugging something else entirely). In the real world, it seems unlikely to cause an actual problem. It is a read not a write so it can't corrupt any memory. However, it could potentially fall off the end of a page and cause an accvio bug.
Which versions are affected by CVE-2026-80749?
How do I fix CVE-2026-80749?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-80749 being exploited?
There is no known exploitation of CVE-2026-80749 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-80749, DEBIAN-CVE-2026-80749, GHSA-4qvv-f8j2-942j, UBUNTU-CVE-2026-80749.