CVE-2026-64830

HIGH 8.8

FFmpeg 2.1 - 8.1.2 Heap Buffer Overflow via VobSub Subtitle Demuxer

CVSS Score

8.8

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-122
Vendor	ffmpeg
Product	ffmpeg
Published	Jul 22, 2026
Last Updated	Jul 22, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Affected Versions

FFmpeg / FFmpeg

2.1 ≤ 8.1.2 dbd495f066a85ba96b17433f4306582aa37c3951

References

NVD ↗ CVE.org ↗ EPSS Data ↗

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

Credits

Pavel Kohout, Aisle Research