The Clean Login WordPress plugin before 1.13.7 does not validate and escape some of its shortcode attributes before outputting them back in the page, which could allow users with a role as low as contributor to perform Stored Cross-Site Scripting attacks which could be used against high privilege users such as admins.
The clean-login plugin before 1.5.1 for WordPress has reflected XSS.
CSRF in the Clean Login plugin before 1.8 for WordPress allows remote attackers to change the login redirect URL or logout redirect URL.