Buffer overflow in PHP
CVE-2025-1218
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.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 3.4 (Low). Vector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:L/I:N/A:N.
EPSS exploit prediction
EPSS: 0.003 (20.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 21st percentile — 20.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001
Affected products
Weakness classification (CWE)
References
- github.com/php/php-src/security/advisories/GHSA-r6x9-5r99-36j7 (Exploit, vendor-advisory, Vendor Advisory)
Frequently asked questions
- What is CVE-2025-1218?
- CVE-2025-1218 is a low-severity vulnerability in PHP, classified under Heap-based Buffer Overflow. CVSS score: 3.4/10. Published 2026-09-25.
- How severe is CVE-2025-1218?
- Low severity. CVSS v3 base score is 3.4 out of 10.