Description
An integer overflow in the MessagePack\BufferUnpacker component of rybakit/msgpack versions prior to 0.11.0 allows attackers to cause a denial of service via crafted MessagePack input when the application runs on 32-bit PHP
References4
Metrics
- CVSS 3.1
-
7.5
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - EPSS — exploit probability
- 0% percentile: 5 · as of 3 November 2026
- CWE
- CWE-190CWE-400
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.