In PHP 5, the rand() and mt_rand() functions are not cryptographically secure. They are pseudo-random number generators (PRNGs) that are predictable if an attacker can observe enough output (like a generated CSRF token or password reset link).
PHP 5.6.40 is significant because it was the last release before the PHP team ceased all active support and security patching for the 5.x branch. php version 5640 vulnerabilities verified
While the specific text "php version 5640 vulnerabilities verified" appears to be a user-generated comment or scan result rather than a single authoritative review, it likely refers to security assessments of . In PHP 5, the rand() and mt_rand() functions
If you see 5.6.40-0+deb9u1 (Debian) or 5.6.400 (custom compile), treat as . While the specific text "php version 5640 vulnerabilities
This list is not exhaustive. Security advisories from Debian and other LTS (Long Term Support) providers list dozens of other CVEs affecting PHP 5.6.40, including those related to file renaming, SSRF bypasses, and crashes in the SOAP and Firebird extensions.
PHP 5.6.40 is considered an version. According to PHP End-of-Life Dates (2026) , only PHP versions 8.2 and newer receive security patches as of early 2026. This means any vulnerability found in PHP 5.6.40 since 2019 will never be fixed by the official PHP team, making any application running it a sitting duck. Verified Vulnerabilities and Security Risks
If a hacker controls a string input and you compare it to a hash or a number, PHP 5 might convert it unexpectedly.