# CVE-2024-21886: Xorg-x11-server: heap buffer overflow in disabledevice

> Heap buffer overflow in X.Org server allows remote code execution or crash in SSH X11 forwarding environments.

- **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:** 28 Feb 2024
- **Updated:** 6 Nov 2025
- **Also known as:** AZL-35404, AZL-44568, BELL-CVE-2024-21886, DEBIAN-CVE-2024-21886, GHSA-vx3h-cj8w-2h2c, UBUNTU-CVE-2024-21886

## What is CVE-2024-21886?

CVE-2024-21886 is a high-severity memory corruption vulnerability in Red Hat Enterprise Linux 6, published on 28 Feb 2024. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A heap buffer overflow flaw was found in the DisableDevice function in the X.Org server. This issue may lead to an application crash or, in some circumstances, remote code execution in SSH X11 forwarding environments.

Weakness: CWE-122 (Heap-based Buffer Overflow)

## Which versions are affected by CVE-2024-21886?


## How do I fix CVE-2024-21886?

Apply the vendor's patch.

## Is CVE-2024-21886 being exploited?

There is no known exploitation of CVE-2024-21886 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-21886 and fix it if it is affected.

What it is: CVE-2024-21886 is a high-severity memory corruption vulnerability in Red Hat Enterprise Linux 6, published on 28 Feb 2024. 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-2024-21886 in the wild and no public exploit code.

Affected product: Red Hat Enterprise Linux 6. 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-2024-21886/ (Markdown: https://insights.sbomify.com/CVE-2024-21886/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-21886
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-21886
- OSV: https://osv.dev/vulnerability/CVE-2024-21886

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-21886/
Summaries are generated and may contain mistakes; the official description above is the record.