CVE-2026-64830 · Symaro Security Advisory

Description

FFmpeg versions 2.1 through 8.1.2 contains a heap buffer overflow vulnerability in the VobSub subtitle demuxer that allows attackers to corrupt adjacent heap memory by supplying a malicious .sub/.idx subtitle file declaring more distinct stream IDs than the fixed-size array bounds in libavformat/mpeg.c. Attackers can craft a subtitle file with excessive distinct stream IDs to trigger unbounded writes beyond the vobsub->q[] array boundary via ff_subtitles_queue_insert(), potentially achieving arbitrary code execution in any application using FFmpeg's VobSub demuxer.

Severity (CVSS)

Base score	8.7
Severity	High
Version	CVSS 4.0
Vector	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Provided by	CNA

Weaknesses

CWE-122 — Heap-based Buffer Overflow

Affected products

Vendor	Product	Versions
FFmpeg	FFmpeg	2.1 to <=8.1.2; dbd495f066a85ba96b17433f4306582aa37c3951

References

https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/23657 (issue-tracking)
https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/dbd495f066a85ba96b17433f4306582aa37c3951 (patch)
https://www.vulncheck.com/advisories/ffmpeg-heap-buffer-overflow-via-vobsub-subtitle-demuxer (third-party-advisory)

Authoritative sources

This page is a snapshot. For the latest enrichment and updates, view the record on CVE.org or the NVD.

Generated from the official CVE List on 23 Jul 2026 07:04 UTC.