---
id: CVE-2026-125256
title: FFmpeg through 9.0.2 Heap Buffer Overflow via RISC-V Vector diff_bytes Routine
summary: >-
  FFmpeg through 9.0.2 contains a heap buffer overflow vulnerability in
  ff_llvidenc_diff_bytes_rvv() that allows attackers to corrupt heap memory by
  triggering negative length values in the Huffyuv encoder. Attackers can supply
  RGB video n…
severity: high
cvss: 7
cvssVector: 'CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H'
cvssSource: cna
cwe:
  - CWE-787
vendor: FFmpeg
product: FFmpeg
affected:
  - FFmpeg >= 7.0 <= 9.0.2
published: '2026-11-09'
updated: '2026-11-09'
sourceUpdated: '2026-11-09T19:12:00.407Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-125256'
references:
  - url: 'https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/25573'
  - url: >-
      https://github.com/FFmpeg/FFmpeg/commit/1f7bdea654a8a9a1761759e22d83943371cff21f
    label: Patch Commit
  - url: >-
      https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/riscv/llvidencdsp_rvv.S#L26
  - url: 'https://github.com/FFmpeg/FFmpeg'
  - url: >-
      https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-heap-buffer-overflow-via-risc-v-vector-diff-bytes-routine
    label: >-
      VulnCheck Advisory: FFmpeg through 9.0.2 Heap Buffer Overflow via RISC-V
      Vector diff_bytes Routine
tags:
  - cve.org
ingestedAt: '2026-11-09T20:27:27.084Z'
---

## Overview

FFmpeg through 9.0.2 contains a heap buffer overflow vulnerability in ff_llvidenc_diff_bytes_rvv() that allows attackers to corrupt heap memory by triggering negative length values in the Huffyuv encoder. Attackers can supply RGB video narrower than 8 or 16 pixels for huffyuv transcoding on RVV-enabled RISC-V builds, causing writes past the encoder's temp buffer.

## Affected

- `FFmpeg >= 7.0 <= 9.0.2`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.