FFMPEG · CVE-2026-125221 · Runtime
NO FIX YET · SEE WHAT TO DO
FFmpeg through 9.0.2 recurses without limit in score_header() in the FLAC parser, so a crafted FLAC file exhausts the thread stack. An attacker who gets a program to demux the file can crash that process.
first public Nov 9, 2026 · 1 source
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Systems that run FFmpeg's demuxer on FLAC files from untrusted sources, such as media upload, transcoding or thumbnail services. Desktop use on files you trust is much less exposed. Teams that never feed external audio to FFmpeg can skip it.
Not affected if no-untrusted-flac-input, trusted-files-only
Who cares ffmpeg, media-processing, self-hosted
ffmpeg -version and compare against the fixed version in the patch linked from NVD.FFmpeg through 9.0.2 contains an uncontrolled recursion vulnerability in score_header() in libavcodec/flac_parser.c that allows attackers to exhaust the thread stack via crafted FLAC input. Attackers can supply a FLAC stream packed with many small valid-looking frame headers, forcing deep recursion that crashes the process during demuxing or parsing.
This page as .md · .json · CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
NVD data is provided by NIST and is public domain. Posts quoted belong to their authors.
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