# CVE-2026-12892: Gstreamer1-plugins-bad-free: gstreamer1-plugins-bad: 1-byte heap out-of-bounds read in h.264 nal extension slice parser

> A 1-byte heap out-of-bounds read in GStreamer's H.264 parser allows attackers to crash applications or leak memory via malicious video files.

- **Severity:** Medium 4.4 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 23 Jun 2026
- **Updated:** 10 Sep 2026
- **Also known as:** DEBIAN-CVE-2026-12892, ECHO-f069-e7ae-e4f6, GHSA-mc62-3gf7-rphg, UBUNTU-CVE-2026-12892

## What is CVE-2026-12892?

CVE-2026-12892 is a medium-severity memory corruption vulnerability in Gstreamer Gstreamer, published on 23 Jun 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

A flaw was found in GStreamer's gst-plugins-bad package. When processing a specially crafted H.264 video file containing malformed MVC or SVC extension slice NAL units, a 1-byte heap out-of-bounds read can occur during parsing. This happens when the parser attempts to check slice boundary information without first verifying that the NAL unit contains enough data beyond the extension header. An attacker could exploit this by tricking a user into opening a malicious H.264 video file, potentially causing the application to crash or leak a single byte of heap memory.

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2026-12892?

It affects 2 products.


Products: Gstreamer Gstreamer, Redhat Enterprise Linux.

## How do I fix CVE-2026-12892?

Apply the vendor's patch.

## Is CVE-2026-12892 being exploited?

There is no known exploitation of CVE-2026-12892 in the wild and no public exploit code.

## Other vulnerabilities in Gstreamer Gstreamer

- [CVE-2026-3083](https://insights.sbomify.com/CVE-2026-3083/): GStreamer rtpqdm2depay Out-Of-Bounds Write Remote Code Execution Vulnerability (high 8.8)
- [CVE-2026-3085](https://insights.sbomify.com/CVE-2026-3085/): GStreamer rtpqdm2depay Heap-based Buffer Overflow Remote Code Execution Vulnerability (high 8.8)
- [CVE-2023-37328](https://insights.sbomify.com/CVE-2023-37328/): GStreamer PGS File Parsing Heap-based Buffer Overflow Remote Code Execution Vulnerability (high 8.8)
- [CVE-2023-37329](https://insights.sbomify.com/CVE-2023-37329/): GStreamer SRT File Parsing Heap-based Buffer Overflow Remote Code Execution Vulnerability (high 8.8)
- [CVE-2023-38103](https://insights.sbomify.com/CVE-2023-38103/): GStreamer RealMedia File Parsing Integer Overflow Remote Code Execution Vulnerability (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-12892 and fix it if it is affected.

What it is: CVE-2026-12892 is a medium-severity memory corruption vulnerability in Gstreamer Gstreamer, published on 23 Jun 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-12892 in the wild and no public exploit code.

Affected product: Gstreamer Gstreamer. 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-2026-12892/ (Markdown: https://insights.sbomify.com/CVE-2026-12892/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-12892
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-12892
- OSV: https://osv.dev/vulnerability/CVE-2026-12892

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-12892/
Summaries are generated and may contain mistakes; the official description above is the record.