# CVE-2026-80887: drm/vmwgfx: use check_add_overflow for shader size+offset bound

> Integer overflow in vmwgfx driver allows bypassing bounds checks, potentially leading to privilege escalation or code execution via crafted shader offsets.

- **Severity:** Not scored
- **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:** Yes
- **Published:** 4 Sep 2026
- **Updated:** 4 Sep 2026
- **Also known as:** AZL-99603, BELL-CVE-2026-80887, DEBIAN-CVE-2026-80887, GHSA-377r-p949-gf93, UBUNTU-CVE-2026-80887

## What is CVE-2026-80887?

CVE-2026-80887 is a vulnerability in Linux, published on 4 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/vmwgfx: use check_add_overflow for shader size+offset bound

vmw_shader_define() validates the user-supplied shader window against
its backing buffer with

	(u64)buffer->tbo.base.size < (u64)size + (u64)offset

drm_vmw_shader_create_arg::offset is __u64 in the uapi; when it is
near U64_MAX the unsigned addition wraps and the resulting tiny value
passes the check.  The unbounded offset is then stored in
res->guest_memory_offset and forwarded to host SVGA shader-create
commands.

Use check_add_overflow() to detect the wrap and compare the resulting
endpoint against the buffer size.

## Which versions are affected by CVE-2026-80887?


## How do I fix CVE-2026-80887?

Apply the vendor's patch.

## Is CVE-2026-80887 being exploited?

There is no known exploitation of CVE-2026-80887 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-80887 and fix it if it is affected.

What it is: CVE-2026-80887 is a vulnerability in Linux, published on 4 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-80887 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-80887/ (Markdown: https://insights.sbomify.com/CVE-2026-80887/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-80887
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-80887
- OSV: https://osv.dev/vulnerability/CVE-2026-80887

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-80887/
Summaries are generated and may contain mistakes; the official description above is the record.