---
id: "CVE-2026-125100"
page: "https://infrastack.ai/live/CVE-2026-125100"
kind: "vulnerability"
aliases: ["CVE-2026-125100"]
title: "FFmpeg: OpenEXR decoder integer overflow leaks uninitialized memory from crafted images"
severity: "medium"
cvss: 4.8
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["ffmpeg", "libavcodec", "media-processing", "package"]
not_affected_if: ["no-exr-decoding", "trusted-input-only"]
published_at: "2026-11-09T19:16:51+00:00"
first_seen_at: "2026-11-09T19:28:16+00:00"
updated_at: "2026-11-09T19:33:36+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-125100", "first_seen_at": "2026-11-09T19:28:16+00:00"}]
exploit_sources: []
---

# FFmpeg: OpenEXR decoder integer overflow leaks uninitialized memory from crafted images

Link for people: https://infrastack.ai/live/CVE-2026-125100 (this .md is for agents)

FFmpeg's OpenEXR decoder miscalculates the tiled block count in decode_frame() in libavcodec/exr.c when handed a crafted tiled image with large dimensions and small tiles. An attacker who supplies such a file can skip decoding and read uninitialized memory or stale frame data.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Run `ffmpeg -version` and compare against the fixed release named in the product data (unknown if the sources do not give it)
- Check whether your build includes the OpenEXR decoder (`ffmpeg -decoders | grep exr`)

## Timeline

- 2026-11-09T19:28:16+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-125100

## Documents

- [advisory] Third-party advisory: www.vulncheck.com https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-integer-overflow-in-openexr-decoder-tile-count
- [fix] Patch: github.com https://github.com/FFmpeg/FFmpeg/commit/c05d46ea2919da83233bf4216d3f58428bb54c59

## From the sources

FFmpeg through 9.0.2 contains an integer overflow vulnerability in the OpenEXR decoder's decode_frame() in libavcodec/exr.c that miscalculates the tiled block count. Attackers can supply a crafted tiled OpenEXR image with large dimensions and small tiles to skip decoding and disclose uninitialized memory or stale frame data.

---

_Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai_