---
id: CVE-2026-75147
title: FFmpeg Out-of-Bounds Read in AV1 RTP Packetizer via rtpenc_av1.c
summary: >-
  FFmpeg before commit 983dae9 contains an out-of-bounds read in the AV1 RTP
  packetizer (libavformat/rtpenc_av1.c). The keyframe detection loop that
  searches for a sequence header OBU advanced its pointer and remaining-size
  counter by the …
severity: high
cvss: 7.1
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H'
cvssSource: cna
cwe:
  - CWE-125
vendor: FFmpeg
product: FFmpeg
affected:
  - FFmpeg < 983dae9c19f46c87d597598c0fd2f2fcee0ad2f8
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-08-25T02:19:23.151938Z'
published: '2026-08-19'
updated: '2026-10-27'
sourceUpdated: '2026-10-27T10:14:33.598Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-75147'
references:
  - url: 'https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/24096'
    label: Pull Request
  - url: >-
      https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/983dae9c19f46c87d597598c0fd2f2fcee0ad2f8
    label: Patch Commit
  - url: >-
      https://www.vulncheck.com/advisories/ffmpeg-out-of-bounds-read-in-av1-rtp-packetizer-via-rtpenc-av1-c
tags:
  - cve.org
epss: 0.00121
epssPercentile: 0.01894
ingestedAt: '2026-10-27T16:11:59.276Z'
---

## Overview

FFmpeg before commit 983dae9 contains an out-of-bounds read in the AV1 RTP packetizer (libavformat/rtpenc_av1.c). The keyframe detection loop that searches for a sequence header OBU advanced its pointer and remaining-size counter by the encoded header length plus the OBU payload size without first bounding the OBU size against the remaining data. A crafted OBU size causes the remaining-size counter to wrap to a positive value, causing the next loop iteration to dereference a pointer beyond the end of the packet buffer. A crafted AV1 input packet muxed to RTP triggers the out-of-bounds read.

## Affected

- `FFmpeg < 983dae9c19f46c87d597598c0fd2f2fcee0ad2f8`

## Remediation

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