What is CVE-2026-125234?

CVE-2026-125234 is a medium-severity vulnerability in Ffmpeg, classified under Integer Overflow or Wraparound. CVSS score: 5.5/10. Published 2026-11-09.

How severe is CVE-2026-125234?

Medium severity. CVSS v3 base score is 5.5 out of 10.

Integer overflow in Ffmpeg

CVE-2026-125234

FFmpeg through 9.0.2 contains an integer overflow vulnerability in wavpack_encode_init() in libavcodec/wavpackenc.c that causes an infinite loop when computing block size from sample rate and channel count. Attackers can supply a crafted audio file, such as a WAV header declaring a huge sample rate with many channels, to hang applications transcoding to WavPack.

Vulnerability class: Integer Overflow

Published 2026-11-09 · last modified 2026-11-09.

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

Ffmpeg

Weakness classification (CWE)

CWE-190 — Integer Overflow or Wraparound

References

code.ffmpeg.org/FFmpeg/FFmpeg/pulls/25694 (issue-tracking)
github.com/FFmpeg/FFmpeg (product)
github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/wavpackenc.c (technical-description)
github.com/FFmpeg/FFmpeg/commit/e621da8ecdbef8edb8336cc899b962159dc2465c (patch)
www.vulncheck.com/advisories/ffmpeg-through-9.0.2-wavpack-encoder-integer-overf… (third-party-advisory)

Frequently asked questions

What is CVE-2026-125234?: CVE-2026-125234 is a medium-severity vulnerability in Ffmpeg, classified under Integer Overflow or Wraparound. CVSS score: 5.5/10. Published 2026-11-09.
How severe is CVE-2026-125234?: Medium severity. CVSS v3 base score is 5.5 out of 10.