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

highCVSS 8.8CVE-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.

Details

Source: NVD Recent CVEs (US · database · site)
Severity: high — CVSS 8.8
Published: 2026-07-22
Last updated: 2026-07-28
Exploitation: Not in CISA KEV at last sync

Original advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-64830

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-648300.35% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 27% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-64830	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

high[NEW] [high] ffmpeg: Multiple vulnerabilitiescert-bund

Recent advisories for FFmpeg

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

highCVE-2026-67290: FreeRDP before 3.29.0 contains a heap out-of-bounds read vulnerability in the TSMF FFmpeg deco…nvd · 2026-08-01
high[UPDATE] [high] ffmpeg: Vulnerability allows code execution and Denial of Servicecert-bund · 2026-07-31
high[NEW] [high] ffmpeg: Multiple vulnerabilitiescert-bund · 2026-07-27
medium[UPDATE] [medium] ffmpeg: Vulnerability allows Denial of Servicecert-bund · 2026-07-27
highCVE-2026-66041: FFmpeg 7.0 through 8.1.2, fixed in commit 4da9812, contains a heap out-of-bounds write vulnera…nvd · 2026-07-24
highCVE-2026-66040: FFmpeg through 8.1.2, fixed in commit b506faf, contains a heap out-of-bounds write vulnerabili…nvd · 2026-07-24