: The official PHP website often has a section on security where you can find information on known vulnerabilities, how to report them, and advisories.
: Tiny cracks in how the server handled data, potentially allowing an attacker to crash the system. php version 5640 vulnerabilities link
After 5.6.40 was released, many critical CVEs were discovered that affect the 5.6 branch but were for 5.6.x. Examples include: : The official PHP website often has a
Using PHP 5.6.40 in 2026 is considered high-risk. Automated scanners frequently identify hundreds of known vulnerabilities in environments running this version. Snyk - Vulnerability report for Docker php:5.6.40-apache how to report them