CVE-2026-125101 (CVSS 3.3)

Description

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.

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CVSS v3.1 Score

3.3

LOW

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

EPSS — Exploit Prediction

0.0013

Probability of exploitation

0.03%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-908 CWE-908

References

Other References

https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/25716 https://github.com/FFmpeg/FFmpeg https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/vmnc.c#L348 https://github.com/FFmpeg/FFmpeg/commit/50865f20b1f474e6b11735c88f668751bc9aa528 https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-vmnc-decoder-uninitialized-heap-memory-disclosure

Frequently Asked Questions

What is 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. It has a CVSS v3.1 base score of 3.3 (LOW).

How severe is CVE-2026-125101? +

CVE-2026-125101 has a CVSS v3.1 score of 3.3 out of 10, rated LOW. This is a low-severity vulnerability with limited impact. The EPSS score is 0.0013, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-125101? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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