High severity · published Jul 22, 2026
CVE-2026-64830
FFmpeg 2.1 - 8.1.2 Heap Buffer Overflow via VobSub Subtitle Demuxer
8.8
CVSS
0.6%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.6% · higher than 51% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
FF
FFmpeg · FFmpeg
2.1 through 8.1.2; dbd495f066a85ba96b17433f4306582aa37c3951 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-64830
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-64830
Patch
https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/dbd495f066a85ba96b17433f4306582aa37c3951
Issue Tracking
https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/23657
Third Party Advisory
https://www.vulncheck.com/advisories/ffmpeg-heap-buffer-overflow-via-vobsub-subtitle-demuxer
More from FFmpeg
9.8
CVE-2026-75143
FFmpeg Heap Buffer Overflow via RIST Protocol Reader
9.8
CVE-2026-40962
FFmpeg before 8.1 has an integer overflow and resultant out-of-bounds write via CENC (Common Encryption) subsample data to libavformat/mov.c
9.8
CVE-2024-35368
FFmpeg n7.0 is affected by a Double Free via the rkmpp_retrieve_frame function within libavcodec/rkmppdec.c
9.8
CVE-2024-31581
FFmpeg version n6.1 was discovered to contain an improper validation of array index vulnerability in libavcodec/cbs_h266_syntax_template.c
9.8
CVE-2024-22862
Integer overflow vulnerability in FFmpeg before n6.1, allows remote attackers to execute arbitrary code via the JJPEG XL Parser