# CVE-2026-8461: FFmpeg libavcodec out-of-bounds write in MagicYUV decoder

Source: https://junglewise.ai/threats/cve-2026-8461-ffmpeg-libavcodec-out-of-bounds-write-in-magicyuv-decoder  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-18. Updated: 2026-06-20  
License: CC BY 4.0 with a link back

CVE-2026-8461 · Severity: high · CVSS 8.8 · Published 2026-06-18

FFmpeg is a widely used software library for processing video and audio files. A vulnerability in its MagicYUV video decoder could allow an attacker to crash applications using the library or potentially execute unauthorized code if a user is tricked into opening a specially crafted video file. This could lead to service disruptions or the compromise of systems that process user-uploaded media.

Technologies: [Ffmpeg](https://junglewise.ai/threats/technologies/ffmpeg). Vendors: [Ffmpeg](https://junglewise.ai/threats/vendors/ffmpeg).

## Quick answers

**Is CVE-2026-8461 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-8461 being exploited in the wild.

**How severe is CVE-2026-8461?** High severity, with a CVSS score of 8.8, published 18 June 2026.

**Which products and versions are affected?** Ffmpeg < 8.1.2.

**Is there a fix for CVE-2026-8461?** A patch was published on 2026-05-25: Fix merged into FFmpeg master branch Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-8461 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-8461?** Check whether you run Ffmpeg at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

An out-of-bounds write vulnerability (CWE-787) exists in FFmpeg's libavcodec/magicyuv.c due to a failure to properly validate slice_height alignment with chroma vshift. An attacker can exploit this by providing a maliciously crafted MagicYUV video file. When processed by the decoder, the misalignment leads to an out-of-array access. This can result in a denial-of-service (crash) or remote code execution under certain conditions. The issue is fixed in FFmpeg version 8.1.2 by rejecting slice_height values that are misaligned with chroma vertical shifting.

## Affected products

- FFmpeg FFmpeg < 8.1.2

## Timeline

- 2026-05-25: patched: Fix merged into FFmpeg master branch
- 2026-06-18: advisory: CVE published by JFrog/NVD

## References

- [https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/23159](https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/23159)

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