An issue was discovered in phpMyAdmin. An attacker can determine whether a user is logged in to phpMyAdmin. The user's session, username, and password are not compromised by this vulnerability. All 4.6.x versions (prior to 4.6.4), 4.4.x versions (prior to 4.4.15.8), and 4.0.x versions (prior to 4.0.10.17) are affected.
https://www.phpmyadmin.net/security/PMASA-2016-48