---
id: CVE-2026-107676
title: >-
  FFmpeg through 9.0.2 contains an uninitialized memory disclosure vulnerability
  in av_dynamic_hdr_plus_to_t35() that leaves up to three payload bytes
  uninitialized when tone_mapping_flag is 0
summary: >-
  FFmpeg through 9.0.2 contains an uninitialized memory disclosure vulnerability
  in av_dynamic_hdr_plus_to_t35() that leaves up to three payload bytes
  uninitialized when tone_mapping_flag is 0. Attackers can supply crafted
  Matroska T.35 Bl…
severity: low
cvss: 3.3
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N'
cwe:
  - CWE-908
vendor: FFmpeg
product: FFmpeg
affected:
  - FFmpeg <= 9.0.2
published: '2026-10-08'
updated: '2026-10-08'
sourceUpdated: '2026-10-08T21:04:38.633'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-107676'
references:
  - url: >-
      https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/2c2f6e96e31795ae95a8f8323a493ffbc493111f
    label: disclosure@vulncheck.com
  - url: 'https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/24590'
    label: disclosure@vulncheck.com
  - url: 'https://ffmpeg.org/'
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavutil/hdr_dynamic_metadata.c#L374-L385
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-uninitialized-memory-disclosure-via-hdr10-metadata-serializer
    label: disclosure@vulncheck.com
tags:
  - nvd
  - cve.org
ingestedAt: '2026-10-08T15:49:37.998Z'
---

## Overview

FFmpeg through 9.0.2 contains an uninitialized memory disclosure vulnerability in av_dynamic_hdr_plus_to_t35() that leaves up to three payload bytes uninitialized when tone_mapping_flag is 0. Attackers can supply crafted Matroska T.35 BlockAdditional or HEVC/AV1 SEI metadata so that remuxing or transcoding writes leaked process memory into output files.

## Remediation

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