What is CVE-2026-125101?

CVE-2026-125101 is a low-severity vulnerability in Ffmpeg, classified under Use of Uninitialized Resource. CVSS score: 3.3/10. Published 2026-11-09.

How severe is CVE-2026-125101?

Low severity. CVSS v3 base score is 3.3 out of 10.

Vulnerability in Ffmpeg

CVE-2026-125101

FFmpeg through 9.0.2 contains an information disclosure vulnerability in the VMnc decoder in libavcodec/vmnc.c that restores an unwritten cursor save area into later frames. Attackers can supply a crafted VMnc stream where a frame fails after loading a cursor shape, causing uninitialized heap bytes from screendta to appear in decoded output.

Published 2026-11-09.

CVSS v3 metric

CVSS v3 base score 3.3 (Low). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N.

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-908 — Use of Uninitialized Resource

References

code.ffmpeg.org/FFmpeg/FFmpeg/pulls/25716 (issue-tracking)
github.com/FFmpeg/FFmpeg (product)
github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/vmnc.c (technical-description)
github.com/FFmpeg/FFmpeg/commit/50865f20b1f474e6b11735c88f668751bc9aa528 (patch)
www.vulncheck.com/advisories/ffmpeg-through-9.0.2-vmnc-decoder-uninitialized-he… (third-party-advisory)

Frequently asked questions

What is CVE-2026-125101?: CVE-2026-125101 is a low-severity vulnerability in Ffmpeg, classified under Use of Uninitialized Resource. CVSS score: 3.3/10. Published 2026-11-09.
How severe is CVE-2026-125101?: Low severity. CVSS v3 base score is 3.3 out of 10.