Search the NVD CVE Portal using the keyword "PHP 5.6.40" to view CVSS severity scores, technical breakdowns, and exploitability vectors.
This is a crucial point of confusion. Because PHP 5.6 is end-of-life, . However, long-term support (LTS) vendors like Debian have backported fixes to their specific php5 packages. This means that while your system may report PHP version 5.6.40, it could be a Debian-specific build (e.g., 5.6.40+dfsg-0+deb8u19 ) that contains additional, unofficial security patches. php version 5640 vulnerabilities link
The dangers of running PHP 5.6.40 extend beyond native language bugs. Legacy environments usually depend on outdated operating systems and companion packages: PHP 5.6: Why you should upgrade - Influential Software Search the NVD CVE Portal using the keyword "PHP 5