The following are minimum requirements:
PHP 7.2 or newer
MySQL 5.7 and newer
All of the add-ons listed here require XenForo 2.3.
Enhanced Search requires at least Elasticsearch 7.2
Note: Only the PHP version requirements have changed here. However, even if you're running PHP 7.2 we strongly recommend upgrading to PHP 8.3 at the earliest opportunity for improvements in speed, security and stability. We also recommend MySQL 8.0 (or equivalent).