---
id: "CVE-2025-52290"
kind: "vulnerability"
aliases: ["CVE-2025-52290"]
title: "FFmpeg: crafted media file crashes decoder via H.264 null pointer"
severity: "high"
cvss: 7.5
epss: null
exploited: false
status: "open"
category: "package"
products: [{"name": "ffmpeg", "fixed": [], "affected": "N-119856-gbe46370941 (full range unknown)", "ecosystem": "vendor"}]
ecosystems: []
tags: ["denial-of-service", "ffmpeg", "libavcodec", "media-processing", "package", "self-hosted"]
not_affected_if: ["no-h264-decoding", "no-untrusted-media"]
published_at: "2026-10-19T18:16:58+00:00"
first_seen_at: "2026-10-23T21:57:18+00:00"
updated_at: "2026-10-25T03:40:17+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-52290", "first_seen_at": "2026-10-23T21:57:18+00:00"}, {"source": "analyst", "url": null, "first_seen_at": "2026-10-25T03:40:17+00:00"}]
---

# FFmpeg: crafted media file crashes decoder via H.264 null pointer

A NULL pointer dereference in the avpriv_h264_has_num_reorder_frames function of FFmpeg N-119856 lets a crafted media file crash the process. An attacker gets a denial of service, not code execution, according to the source description.

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

## Affected

- vendor:ffmpeg affected N-119856-gbe46370941 (full range unknown) fixed ?

## How to check

- Run `ffmpeg -version`; a git build at or near N-119856-gbe46370941 is the tested one. Distro/release builds are not stated as affected or unaffected.
- Reproduce on a test box only: `ffmpeg -i 1_poc.mp4 -f null -` with the public sample; a crash (SEGV in avpriv_h264_has_num_reorder_frames) means exposed.
- Check whether any upload, transcoding or thumbnail pipeline runs ffmpeg/libavformat on untrusted files.

## Fix

unknown: no fixing commit or release identified as of 2026-10-25. Until then, do not feed untrusted media to FFmpeg without sandboxing (separate process, resource limits, auto-restart); re-check ffmpeg.org / git master for a fix to h264dec.c / libavformat/demux.c.

## Timeline

- 2026-10-23T21:57:18+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2025-52290
- 2026-10-25T03:40:17+00:00 analyst — Read reporter's oss-security disclosure: only tested rev N-119856-gbe46370941 (commit be46370941405fb04402d96373a53e2a1846f3ac); no fix commit or fixed release exists in disclosure; range not established; FFmpeg maintainers suggested independent publication. Public PoC sample (1_poc.mp4), no exploitation reported. Nothing verified: no FFmpeg primary advisory/trac found.

## Documents

- [advisory] oss-security: CVE-2025-52290 FFmpeg NULL deref (reporter disclosure) https://www.openwall.com/lists/oss-security/2026/10/20/6
- [mentions] Red Hat: CVE-2025-52290 https://access.redhat.com/security/cve/cve-2025-52290
- [poc] 1_poc.mp4 PoC sample https://github.com/sigdevel/pocs/blob/main/res/FFmpeg/ffmpeg/1/1_poc.mp4

## From the sources

A NULL pointer dereference in the avpriv_h264_has_num_reorder_frames function of Ffmpeg version N-119856-gbe46370941 allows attackers to cause a Denial of Service (DoS) via processing a crafted media file.

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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_