---
id: "CVE-2026-120247"
kind: "vulnerability"
aliases: ["CVE-2026-120247"]
title: "FFmpeg: crafted Huffyuv video leaks heap memory into decoded frames"
severity: "medium"
cvss: 6.8
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["ffmpeg", "media-processing", "package"]
not_affected_if: ["huffyuv-not-used", "untrusted-input-not-decoded"]
published_at: "2026-11-01T01:17:18+00:00"
first_seen_at: "2026-11-01T01:47:22+00:00"
updated_at: "2026-11-01T01:47:38+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-120247", "first_seen_at": "2026-11-01T01:47:22+00:00"}]
---

# FFmpeg: crafted Huffyuv video leaks heap memory into decoded frames

FFmpeg's Huffyuv decoder can be fed a short packed-BGR bitstream that makes it copy uninitialized heap bytes into output video frames. An attacker who supplies a crafted video can read heap memory contents through the decoded pixels.

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

## How to check

- Run `ffmpeg -version` and compare against the affected range 2.3 through 9.0.2.
- Check whether your application or service decodes untrusted Huffyuv video files.

## Timeline

- 2026-11-01T01:47:22+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-120247

## From the sources

FFmpeg 2.3 through 9.0.2 contains a use of uninitialized resource vulnerability in the Huffyuv decoder that allows attackers to leak heap memory into decoded pixels via short packed-BGR bitstreams. Attackers can craft a Huffyuv BGR24/BGRA video whose entropy data ends early, causing decode_slice() to add uninitialized s->temp[0] bytes into output frames, exposing heap contents.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_