# CVE-2026-80786: fbdev: Wrap user-invoked calls to fb_set_var() in helper

> A missing state check in the Linux kernel framebuffer driver allows local users to trigger inconsistent display states, potentially causing system instability or crashes.

- **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:** 21 Oct 2026
- **Also known as:** AZL-99558, BELL-CVE-2026-80786, DEBIAN-CVE-2026-80786, GHSA-p7rm-gj7v-32rv, UBUNTU-CVE-2026-80786

## What is CVE-2026-80786?

CVE-2026-80786 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:

fbdev: Wrap user-invoked calls to fb_set_var() in helper

Handle fbcon during display updates in fb_set_var_from_user(). Check
with fbcon if the mode change is possible, update hardware state and
finally update fbcon. Update all callers.

Only the FBIOPUT_VSCREENINFO ioctl currently does all steps. Other
mode-changes callers in sysfs and driver code are missing fbcon-related
steps.

With the new helper, ps3fb and sh_mobile_lcdcfb no longer maintain
fbcon state themselves.

## Which versions are affected by CVE-2026-80786?


## How do I fix CVE-2026-80786?

Apply the vendor's patch.

## Is CVE-2026-80786 being exploited?

There is no known exploitation of CVE-2026-80786 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-80786 and fix it if it is affected.

What it is: CVE-2026-80786 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-2026-80786 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-2026-80786/ (Markdown: https://insights.sbomify.com/CVE-2026-80786/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-80786
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-80786
- OSV: https://osv.dev/vulnerability/CVE-2026-80786

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-80786/
Summaries are generated and may contain mistakes; the official description above is the record.