# CVE-2026-80579: fbdev: clear fb_info->mode before deleting a videomode

> A use-after-free vulnerability in the Linux kernel fbdev subsystem allows attackers to cause denial of service or potentially execute code via stale pointer dereference.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **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:** 26 Aug 2026
- **Updated:** 16 Oct 2026
- **Also known as:** AZL-97716, BELL-CVE-2026-80579, DEBIAN-CVE-2026-80579, GHSA-ppqm-p5h9-4x92, UBUNTU-CVE-2026-80579

## What is CVE-2026-80579?

CVE-2026-80579 is a high-severity use after free vulnerability in Linux, published on 26 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:

fbdev: clear fb_info->mode before deleting a videomode

fb_set_var() can delete a mode from info->modelist when userspace
passes FB_ACTIVATE_INV_MODE through FBIOPUT_VSCREENINFO. The code
checks that the mode being deleted is not the current info->var and
that fbcon is not using it, but it does not check fb_info->mode.

fb_info->mode may still point into the modelist entry being deleted.
If the entry is freed, later mode sysfs reads through show_mode() can
dereference a stale pointer.

Clear fb_info->mode before calling fb_delete_videomode() when it
matches the mode being removed.

## Which versions are affected by CVE-2026-80579?


## How do I fix CVE-2026-80579?

Apply the vendor's patch.

## Is CVE-2026-80579 being exploited?

There is no known exploitation of CVE-2026-80579 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-80579 and fix it if it is affected.

What it is: CVE-2026-80579 is a high-severity use after free vulnerability in Linux, published on 26 Aug 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-2026-80579 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-2026-80579/ (Markdown: https://insights.sbomify.com/CVE-2026-80579/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-80579
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-80579
- OSV: https://osv.dev/vulnerability/CVE-2026-80579

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-80579/
Summaries are generated and may contain mistakes; the official description above is the record.