---
id: CVE-2026-75143
title: FFmpeg Heap Buffer Overflow via RIST Protocol Reader
summary: >-
  FFmpeg before commit 1c10bcc contains a heap buffer overflow in the RIST
  protocol reader (libavformat/librist.c). librist_read() ignored its size
  argument and copied the full received payload length into the caller-provided
  destination b…
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cvssSource: cna
cwe:
  - CWE-122
vendor: FFmpeg
product: FFmpeg
affected:
  - FFmpeg < 1c10bcc2e17255dacb717a25ab3db142ce390602
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: total
  timestamp: '2026-08-20T00:00:00+00:00'
published: '2026-08-19'
updated: '2026-10-27'
sourceUpdated: '2026-10-27T10:14:30.888Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-75143'
references:
  - url: 'https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/24089'
    label: Pull Request
  - url: >-
      https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/1c10bcc2e17255dacb717a25ab3db142ce390602
    label: Patch Commit
  - url: >-
      https://www.vulncheck.com/advisories/ffmpeg-heap-buffer-overflow-via-rist-protocol-reader
tags:
  - cve.org
epss: 0.00702
epssPercentile: 0.53064
ingestedAt: '2026-10-27T16:11:59.274Z'
---

## Overview

FFmpeg before commit 1c10bcc contains a heap buffer overflow in the RIST protocol reader (libavformat/librist.c). librist_read() ignored its size argument and copied the full received payload length into the caller-provided destination buffer, overflowing it when the payload exceeds the destination size. This is reachable via the async:rist:// URL scheme, where the async wrapper supplies a smaller buffer than the received payload. A remote RIST sender can trigger the overflow by sending a packet whose payload exceeds the caller buffer size.

## Affected

- `FFmpeg < 1c10bcc2e17255dacb717a25ab3db142ce390602`

## Remediation

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