Vulnerability in Ffmpeg
CVE-2026-125226
FFmpeg through 9.0.2 contains an uncontrolled memory allocation vulnerability in sbg_read_header() in libavformat/sbgdec.c that derives an unbounded default frame size from the script's sample rate. Attackers can supply a crafted SBaGen script declaring a very high -r sample rate so the wavesynth decoder allocates enormous audio frames, exhausting memory and causing denial of service.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- code.ffmpeg.org/FFmpeg/FFmpeg/pulls/25703 (issue-tracking)
- github.com/FFmpeg/FFmpeg (product)
- github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavformat/sbgdec.c (technical-description)
- github.com/FFmpeg/FFmpeg/commit/1f4b2e22cfba19f94489ec4a17130f4f0d5d8a0c (patch)
- www.vulncheck.com/advisories/ffmpeg-through-9.0.2-excessive-memory-allocation-v… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-125226?
- CVE-2026-125226 is a medium-severity vulnerability in Ffmpeg, classified under CWE-789. CVSS score: 5.5/10. Published 2026-11-09.
- How severe is CVE-2026-125226?
- Medium severity. CVSS v3 base score is 5.5 out of 10.