What’s Vulnerable › Vulnerabilities

CVE-2026-64830: FFmpeg 2.1 - 8.1.2 Heap Buffer Overflow via VobSub Subtitle Demuxer

• Severity: high (CVSS 8.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.6% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-07-22 · updated 2026-10-24
• Weakness: CWE-122

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.

Affected products

• FFmpeg: from 2.1 through 8.1.2

References

• https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/dbd495f066a85ba96b17433f4306582aa37c3951
• https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/23657
• https://www.vulncheck.com/advisories/ffmpeg-heap-buffer-overflow-via-vobsub-subtitle-demuxer

Get alerted when CVE-2026-64830 or the next vulnerability affects your stack