Description
The mysqlnd wire protocol parser reads fields out of server packets before checking that the packet still holds enough bytes for them. A malicious or compromised MySQL server can send a truncated packet and make the client read past the end of the packet buffer, which is undefined behaviour and can crash the process.
Affected products
php: php; microsoft: windows
References1
- github.com/php/php-src/security/advisories/GHSA-r6x9-5r99-36j7 Vendor AdvisoryExploit
Metrics
- CVSS 3.1
-
5.9
MEDIUM
Score source: NVD
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H - EPSS — exploit probability
- 0% percentile: 21 · as of 9 November 2026
- CWE
- CWE-122
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.