CVE-2026-125229: Memory Corruption (CVSS 7.8)

Description

FFmpeg through 9.0.2 contains an out-of-bounds memory access vulnerability in the encode_frame() function of libavcodec/huffyuvenc.c, because encode_init() never validates minimum frame dimensions for the median predictor. Attackers can supply a tiny video, such as a 2-pixel-wide or 1-2-pixel-tall frame, that causes negative sub_median_pred lengths and out-of-bounds reads and writes when transcoded to huffyuv or ffvhuff, crashing the encoder.

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CVSS v3.1 Score

7.8

HIGH

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

EPSS — Exploit Prediction

0.0013

Probability of exploitation

0.02%

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-787 Out-of-bounds Write

References

Other References

https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/25573 https://github.com/FFmpeg/FFmpeg https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/huffyuvenc.c#L762 https://github.com/FFmpeg/FFmpeg/commit/45f98d0819efe2b7ce93e9034b7e6a4ed6700621 https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-out-of-bounds-memory-access-in-huffyuv-ffvhuff-median-predictor

Frequently Asked Questions

What is CVE-2026-125229? +

FFmpeg through 9.0.2 contains an out-of-bounds memory access vulnerability in the encode_frame() function of libavcodec/huffyuvenc.c, because encode_init() never validates minimum frame dimensions for the median predictor. Attackers can supply a tiny video, such as a 2-pixel-wide or 1-2-pixel-tall frame, that causes negative sub_median_pred lengths and out-of-bounds reads and writes when transcoded to huffyuv or ffvhuff, crashing the encoder. It has a CVSS v3.1 base score of 7.8 (HIGH).

How severe is CVE-2026-125229? +

CVE-2026-125229 has a CVSS v3.1 score of 7.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. 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-2026-125229? +

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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