---
id: "CVE-2026-125254"
page: "https://infrastack.ai/live/CVE-2026-125254"
kind: "vulnerability"
aliases: ["CVE-2026-125254"]
title: "FFmpeg: crafted VVC bitstream crashes the decoder via division by zero"
severity: "medium"
cvss: 6.8
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["ffmpeg", "package", "video-processing", "vvc"]
not_affected_if: ["no-vvc-decoding", "trusted-input-only"]
published_at: "2026-11-09T20:18:11+00:00"
first_seen_at: "2026-11-09T20:48:13+00:00"
updated_at: "2026-11-09T20:49:48+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-125254", "first_seen_at": "2026-11-09T20:48:13+00:00"}]
exploit_sources: []
---

# FFmpeg: crafted VVC bitstream crashes the decoder via division by zero

Link for people: https://infrastack.ai/live/CVE-2026-125254 (this .md is for agents)

FFmpeg through 9.0.2 has a division-by-zero bug in its VVC decoder, because reference list indices are not validated. A crafted VVC video file makes the decoding process crash.

_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 sources.
- Check whether your application decodes untrusted VVC (H.266) input with FFmpeg.

## Timeline

- 2026-11-09T20:48:13+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-125254

## Documents

- [advisory] Third-party advisory: www.vulncheck.com https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-division-by-zero-via-vvc-ff-vvc-slice-rpl
- [fix] Patch: github.com https://github.com/FFmpeg/FFmpeg/commit/8732d7585cd8ab9d1dd9baeb4db5e93466c0efa7

## From the sources

FFmpeg through 9.0.2 contains a division by zero vulnerability in the VVC decoder because ff_vvc_slice_rpl() fails to validate num_ref_idx_active against built reference list entries. Attackers can supply a crafted VVC bitstream whose excess reference indices yield a zero POC difference in ff_vvc_mv_scale(), crashing the decoding process.

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