The Modern Events Calendar Lite WordPress plugin before 6.1.5 does not sanitise and escape the time parameter before using it in a SQL statement in the mec_load_single_page AJAX action, available to unauthenticated users, leading to an unauthenticated SQL injection issue
The Modern Events Calendar Lite WordPress plugin before 5.22.3 does not properly sanitize or escape values set by users with access to adjust settings withing wp-admin.
The Modern Events Calendar Lite WordPress plugin before 5.22.2 does not escape some of its settings before outputting them in attributes, allowing high privilege users to perform Cross-Site Scripting attacks even when the unfiltered_html capability is disallowed.