# CVE-2026-125260: FFmpeg heap buffer overflow in libavcodec/exrenc.c

Source: https://junglewise.ai/threats/cve-2026-125260-ffmpeg-through-9-0-2-contains-a-heap-buffer-overflow  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-09. Updated: 2026-11-09  
License: CC BY 4.0 with a link back

CVE-2026-125260 · Severity: high · CVSS 7 · Published 2026-11-09

FFmpeg is a multimedia transcoding library used to convert video and audio files between formats. A heap buffer overflow in its OpenEXR encoder allows attackers to corrupt memory and crash the application by supplying video files with changing frame dimensions during encoding, potentially enabling remote code execution.

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

## Quick answers

**Is CVE-2026-125260 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-125260 being exploited in the wild.

**How severe is CVE-2026-125260?** High severity, with a CVSS score of 7, published 9 November 2026.

**Which products and versions are affected?** Ffmpeg through 9.0.2.

**Is there a fix for CVE-2026-125260?** Yes: fixed in FFmpeg 9.1. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-125260 attacked?** It is attacked over the network or with local access.

**Am I affected by CVE-2026-125260?** 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.

## How to fix

- Fixed in FFmpeg 9.1

## Technical details

A heap buffer overflow exists in the encode_scanline_rle() function within libavcodec/exrenc.c when processing video frames taller than the encoder's configured height. An attacker can craft input where frame resolution changes mid-stream and transcode it to OpenEXR with RLE compression, causing writes past the scanline array boundary. The vulnerability requires local or network access to supply the malicious input and is triggered during video encoding operations.

## Affected products

- FFmpeg FFmpeg through 9.0.2

## Timeline

- 2026-11-09: disclosed: CVE-2026-125260 published
- 2026-11-05: patched: Fix merged in PR #25682 targeting FFmpeg 9.1 release

## References

- [https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/25682](https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/25682)
- [https://github.com/FFmpeg/FFmpeg](https://github.com/FFmpeg/FFmpeg)

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