CVE-2026-64830: Ffmpeg

High severity, CVSS 8.8. EPSS: 0.6% chance of exploitation in the next 30 days.

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.

Affected products

• Ffmpeg Ffmpeg: from 2.1, up to and including 8.1.2

Published 2026-07-22. Last modified 2026-07-28.