PHP is dead.

According to https://wordpress.org/about/stats/, about 20.23% of #WordPress installs are still running PHP 7.4 or earlier.

If you're in that group, you need to upgrade to a currently supported PHP version (8.2 or newer). PHP 8.5 is the latest stable release: https://www.php.net/supported-versions.php

Emergency patches for two critical RCE vulnerabilities are dropping later today.
https://www.php.net/index.php#2026-10-20-1