CVE details
CVE-2026-64830
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 ports (3)
| Port | Package | Version | Status | Maintainer |
|---|---|---|---|---|
| multimedia/ffmpeg4 | ffmpeg4 | 4.4.8_2 | possibly backported | monwarez@mailoo.org |
| multimedia/ffmpeg3 | ffmpeg3 | 3.0.2_1 | unaddressed | kreinholz@gmail.com |
| multimedia/linux-rl9-ffmpeg | linux-rl9-ffmpeg-libs | 7.1.5 | unaddressed | emulation@FreeBSD.org |
Template for a VuXML entry
Range taken from the CVE record, check it before committing. make newentry in security/vuxml creates the vid.
<vuln vid="FIXME (make newentry)">
<topic>FIXME -- FIXME</topic>
<affects>
<package>
<name>ffmpeg3</name>
<range><lt>FIXME</lt></range>
</package>
<package>
<name>linux-rl9-ffmpeg-libs</name>
<range><lt>FIXME</lt></range>
</package>
</affects>
<description>
<body xmlns="http://www.w3.org/1999/xhtml">
<p>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.</p>
</body>
</description>
<references>
<cvename>CVE-2026-64830</cvename>
<url>https://nvd.nist.gov/vuln/detail/CVE-2026-64830</url>
</references>
<dates>
<discovery>2026-07-22</discovery>
<entry>2026-10-25</entry>
</dates>
</vuln>