Description

A heap buffer overflow in the stbl_AddSize function (isomedia/stbl_write.c) of GPAC MP4Box v2.4 allows attackers to cause a Denial of Service (DoS) via supplying a crafted MP4 file.

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EPSS — Exploit Prediction

0.0020

Probability of exploitation

0.09%

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.

References

Other References

https://github.com/gpac/gpac/commit/321624f28d19a413449fd1718d1eb59037f8f7fc https://github.com/gpac/gpac/issues/3261 https://github.com/sigdevel/pocs/blob/main/res/gpac/MP4Box/25/25_poc.mp4 https://infosec.exchange/@sigdevel/116769271709415444 http://www.openwall.com/lists/oss-security/2026/10/17/2

Frequently Asked Questions

What is CVE-2025-55640? +

A heap buffer overflow in the stbl_AddSize function (isomedia/stbl_write.c) of GPAC MP4Box v2.4 allows attackers to cause a Denial of Service (DoS) via supplying a crafted MP4 file.

How do I check if I'm vulnerable to CVE-2025-55640? +

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.