CVE-2026-125221

medium

Description

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.

References

https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-uncontrolled-recursion-in-flac-parser-score-header

https://github.com/FFmpeg/FFmpeg/commit/972fe1ccd326538fe9a6b5d5094b7880b5443429

https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/flac_parser.c#L603

https://github.com/FFmpeg/FFmpeg

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-120310

https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/25569

Details

Source: Mitre, NVD

Published: 2026-11-09

Updated: 2026-11-10

Risk Information

CVSS v2

Base Score: 4.9

Vector: CVSS2#AV:L/AC:L/Au:N/C:N/I:N/A:C

Severity: Medium

CVSS v3

Base Score: 5.5

Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

Severity: Medium

CVSS v4

Base Score: 6.8

Vector: 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

Severity: Medium

EPSS

EPSS: 0.00165