What is CVE-2026-40962?

CVE-2026-40962 is a medium-severity vulnerability in Ffmpeg, classified under Integer Overflow or Wraparound. CVSS score: 4.9/10. Published 2026-04-16.

How severe is CVE-2026-40962?

Medium severity. CVSS v3 base score is 4.9 out of 10.

Integer overflow in Ffmpeg

CVE-2026-40962

FFmpeg before 8.1 has an integer overflow and resultant out-of-bounds write via CENC (Common Encryption) subsample data to libavformat/mov.c.

Vulnerability class: Integer Overflow

Published 2026-04-16 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 4.9 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L.

EPSS exploit prediction

EPSS: 0.002 (4.2th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 4th percentile — 4.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.001 · newest: 0.002 · change: +0.000

Affected products

Ffmpeg — versions 4.1

Weakness classification (CWE)

CWE-190 — Integer Overflow or Wraparound

References

code.ffmpeg.org/FFmpeg/FFmpeg/pulls/22348 (Patch, Issue Tracking)

Frequently asked questions

What is CVE-2026-40962?: CVE-2026-40962 is a medium-severity vulnerability in Ffmpeg, classified under Integer Overflow or Wraparound. CVSS score: 4.9/10. Published 2026-04-16.
How severe is CVE-2026-40962?: Medium severity. CVSS v3 base score is 4.9 out of 10.