Question 1

What is the EOL Risk Score for PHP 4.0?

Accepted Answer

PHP 4.0 has an EOL Risk Score™ of 90 out of 100, placing it in the Critical risk band. The score is calculated from four factors: EOL Recency (40/40), Attack Surface (30/30), CISA KEV Exposure (20/20), and Extended Support Availability (0/10).

Question 2

Is PHP 4.0 still supported?

Accepted Answer

PHP 4.0 is no longer supported — it has passed its end of life date (June 23, 2001). No further security patches will be issued. Upgrade to a supported version or obtain extended lifecycle support.

Question 3

When does PHP 4.0 reach end of life?

Accepted Answer

PHP 4.0 reached (or will reach) end of life on June 23, 2001. After this date, no security patches or bug fixes are issued by the vendor.

Question 4

What are the security risks of running PHP 4.0 after end of life?

Accepted Answer

After end of life, the vendor's standard support for PHP 4.0 ends, so newly discovered vulnerabilities may never be fixed unless a paid extended support option covers that version. Auditors ask about it too: PCI DSS requirement 12.3.4, for example, calls for a yearly review of vendor end-of-life announcements with a remediation plan approved by senior management.