For government-grade tracking, use the NVD:
PHP version 5.6.40, released in 2018, is one such version that has reached its EOL. This version, like many others before it, had its share of vulnerabilities. Some of the notable vulnerabilities found in PHP 5.6.40 include: php version 5640 vulnerabilities link
Staying on PHP 5.6.40 is widely considered a major security risk today. Security experts at Influential Software and TuxCare emphasize that: For government-grade tracking, use the NVD: PHP version 5