CVE-2026-125231: Null Dereference (CVSS 5.5)

Description

FFmpeg 4.4 through 9.0.2 contains a NULL pointer dereference vulnerability in libavcodec/adxdec.c because adx_decode_header() updates the channel layout before validating the sample rate. Attackers can supply a crafted ADX/AAX stream with mid-stream new-extradata side data carrying an invalid sample rate, causing adx_decode() to write through NULL plane pointers and crash the application.

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CVSS v3.1 Score

5.5

MEDIUM

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

EPSS — Exploit Prediction

0.0017

Probability of exploitation

0.06%

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-476 CWE-476

References

Other References

https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/25703 https://github.com/FFmpeg/FFmpeg https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/adxdec.c#L77 https://github.com/FFmpeg/FFmpeg/commit/515dcad73d77711507083cae3913c9327c0977c6 https://www.vulncheck.com/advisories/ffmpeg-4.4-through-9.0.2-null-pointer-dereference-via-adx-decode-header

Frequently Asked Questions

What is CVE-2026-125231? +

FFmpeg 4.4 through 9.0.2 contains a NULL pointer dereference vulnerability in libavcodec/adxdec.c because adx_decode_header() updates the channel layout before validating the sample rate. Attackers can supply a crafted ADX/AAX stream with mid-stream new-extradata side data carrying an invalid sample rate, causing adx_decode() to write through NULL plane pointers and crash the application. It has a CVSS v3.1 base score of 5.5 (MEDIUM).

How severe is CVE-2026-125231? +

CVE-2026-125231 has a CVSS v3.1 score of 5.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0017, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-125231? +

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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