Open redirect vulnerability in the wp_validate_redirect function in wp-includes/pluggable.php in WordPress before 4.4.2 allows remote attackers to redirect users to arbitrary web sites and conduct phishing attacks via a malformed URL that triggers incorrect hostname parsing, as demonstrated by an https:example.com URL.
https://wpvulndb.com/vulnerabilities/8377
https://wordpress.org/news/2016/02/wordpress-4-4-2-security-and-maintenance-release/
https://core.trac.wordpress.org/changeset/36444
https://codex.wordpress.org/Version_4.4.2
http://www.securitytracker.com/id/1034933