The Contest Gallery WordPress plugin before 19.1.5.1, Contest Gallery Pro WordPress plugin before 19.1.5.1 do not escape the cg_id POST parameter before concatenating it to an SQL query in 0_change-gallery.php. This may allow malicious users with at least author privilege to leak sensitive information from the site's database.
https://wpscan.com/vulnerability/2e993280-1007-4e9d-9ca6-2b5f774e9965