---
id: CVE-2026-75141
title: FFmpeg Heap Buffer Overflow in hvcC Box Writer via HEVC Muxing
summary: >-
  FFmpeg before commit acf5d7c contains a heap buffer overflow in the hvcC box
  writer. When writing an HEVC configuration record with more NAL units of a
  single type than the count field can represent, the NAL unit count overflows,
  causing…
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H'
cvssSource: cna
cwe:
  - CWE-122
vendor: FFmpeg
product: FFmpeg
affected:
  - FFmpeg < acf5d7cdc1f9ae8752c23e1ea8d7f355ed780781
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-08-20T00:00:00+00:00'
published: '2026-08-19'
updated: '2026-10-27'
sourceUpdated: '2026-10-27T10:14:29.483Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-75141'
references:
  - url: 'https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/24088'
    label: Pull Request
  - url: >-
      https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/acf5d7cdc1f9ae8752c23e1ea8d7f355ed780781
    label: Patch Commit
  - url: >-
      https://www.vulncheck.com/advisories/ffmpeg-heap-buffer-overflow-in-hvcc-box-writer-via-hevc-muxing
tags:
  - cve.org
epss: 0.00199
epssPercentile: 0.09653
ingestedAt: '2026-10-27T16:11:59.273Z'
---

## Overview

FFmpeg before commit acf5d7c contains a heap buffer overflow in the hvcC box writer. When writing an HEVC configuration record with more NAL units of a single type than the count field can represent, the NAL unit count overflows, causing a heap buffer overflow. A crafted HEVC input file triggers the overflow during muxing.

## Affected

- `FFmpeg < acf5d7cdc1f9ae8752c23e1ea8d7f355ed780781`

## Remediation

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