The Autoptimize WordPress plugin before 3.1.1 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)
https://wpscan.com/vulnerability/219767a8-2427-42d5-8734-bd197d9ab46b