CVE-2026-64830: FFmpeg 2.1 - 8.1.2 Heap Buffer Overflow via VobSub Subtitle Demuxer
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 ffsubtitlesqueueinsert(), potentially achieving arbitrary code execution in any application using FFmpeg's VobSub demuxer.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
FFmpeg VobSub subtitle demuxerto a version that resolves this vulnerability.Fixed in 8.1.2
Event History
Frequently Asked Questions
What is the severity of CVE-2026-64830?
CVE-2026-64830 has a high severity rating of 8.8.
How do I fix CVE-2026-64830?
To fix CVE-2026-64830, update FFmpeg to a version beyond 8.1.2.
What is the nature of the vulnerability CVE-2026-64830?
CVE-2026-64830 is a heap buffer overflow vulnerability in the VobSub subtitle demuxer.
Who is affected by CVE-2026-64830?
Users of FFmpeg versions 2.1 through 8.1.2 are affected by CVE-2026-64830.
What can attackers achieve with CVE-2026-64830?
Attackers can corrupt adjacent heap memory by supplying a malicious .sub/.idx subtitle file due to CVE-2026-64830.