CVE-2026-80702 drm/vmwgfx: fix guest_memory_dirty bitfield clobbered as size
A bug in the vmwgfx driver causes memory corruption by writing to the wrong field, allowing attackers to read or write past buffer boundaries.
- 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-2026-80702?
CVE-2026-80702 is a high-severity memory corruption vulnerability in Linux, published on 28 Aug 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/vmwgfx: fix guest_memory_dirty bitfield clobbered as size
Two sites in vmwgfx_resource.c assign boolean literals to res->guest_memory_size, which is an unsigned long allocation-size field; the intended target is the adjacent res->guest_memory_dirty bitfield. After the assignments the field holds 0 or 1 instead of the resource's MOB allocation size:
- vmw_resource_release() writes 0 (false), and - vmw_resource_unbind_list() writes 1 (true).
Subsequent revalidation paths read guest_memory_size when computing the dirty page range (vmw_bo_dirty_transfer_to_res()) and the buffer allocation size (vmw_resource_buf_alloc()), producing zero-length walks or wrap-around ranges that read or write past the MOB bitmap. The dirty-tracking intent of the original code (mark the resource as dirtied since the last sync) is also lost, since guest_memory_dirty is never updated.
Rename both assignments to guest_memory_dirty.
Which versions are affected by CVE-2026-80702?
How do I fix CVE-2026-80702?
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-2026-80702 being exploited?
There is no known exploitation of CVE-2026-80702 in the wild and no public exploit code.
Sources
Also known as AZL-98051, BELL-CVE-2026-80702, DEBIAN-CVE-2026-80702, GHSA-736r-87mh-h3gr, UBUNTU-CVE-2026-80702.