The Relevanssi – A Better Search plugin for WordPress is vulnerable to Information Exposure in all versions up to, and including, 4.22.2 via the relevanssi_do_query() due to insufficient limitations on the posts that are returned when searching. This makes it possible for unauthenticated attackers to extract potentially sensitive information from password protected posts.
https://plugins.trac.wordpress.org/changeset/3134753/relevanssi/trunk/lib/common.php