---
id: "CVE-2026-125185"
page: "https://infrastack.ai/live/CVE-2026-125185"
kind: "vulnerability"
aliases: ["CVE-2026-125185"]
title: "FFmpeg: crafted HEVC or VVC file crashes decoder via division by zero"
severity: "medium"
cvss: 6.8
epss: null
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["ffmpeg", "media-processing", "runtime", "video-transcoding"]
not_affected_if: ["trusted-input-only"]
published_at: "2026-11-09T19:16:54+00:00"
first_seen_at: "2026-11-09T19:28:17+00:00"
updated_at: "2026-11-09T19:31:34+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-125185", "first_seen_at": "2026-11-09T19:28:17+00:00"}]
exploit_sources: []
---

# FFmpeg: crafted HEVC or VVC file crashes decoder via division by zero

Link for people: https://infrastack.ai/live/CVE-2026-125185 (this .md is for agents)

FFmpeg through 9.0.2 divides by zero in ff_aom_parse_film_grain_sets() when an AFGS1 film grain scaling point repeats an x value, because the parser does not reject it. An attacker who supplies a crafted HEVC or VVC file with zero-increment scaling points in T.35 SEI messages crashes the decoder.

_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 version in the patch link; the sources give no fixed version.
- Look for FFmpeg in services that decode untrusted HEVC or VVC video, such as upload pipelines or transcoders.

## Timeline

- 2026-11-09T19:28:17+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-125185

## Documents

- [advisory] Third-party advisory: www.vulncheck.com https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-division-by-zero-via-afgs1-film-grain-scaling-points
- [fix] Patch: github.com https://github.com/FFmpeg/FFmpeg/commit/b8daf520dd03f6139aa053acb768f3c4594599d9

## From the sources

FFmpeg through 9.0.2 contains a division by zero vulnerability in ff_aom_parse_film_grain_sets() that fails to reject AFGS1 scaling points with repeated x values. Attackers can supply crafted HEVC or VVC files with zero-increment scaling points in T.35 SEI messages, causing generate_scaling() to divide by zero and crash the decoder.

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