CVE-2023-2159

The CMP – Coming Soon & Maintenance plugin for WordPress is vulnerable to Maintenance Mode Bypass in versions up to, and including, 4.1.7. A correct cmp_bypass GET parameter in the URL (equal to the md5-hashed home_url in the default setting) allows users to visit a site placed in maintenance mode thus bypassing the plugin’s provided feature.

Source: CVE-2023-2159