Cross-site scripting vulnerability exists in WP Admin UI Customize versions prior to ver 1.5.14. If a malicious admin user customizes the admin screen with some malicious contents, an arbitrary script may be executed on the web browser of the other users who are accessing the admin screen.

The WP Admin UI Customize WordPress plugin before 1.5.13 does not sanitise and escape some of its settings, which could allow high privilege users such as admin to perform Stored Cross-Site Scripting attacks even when the unfiltered_html capability is disallowed (for example in multisite setup).