The Responsive Gallery Grid WordPress plugin before 2.3.11 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/fc3beca7-af38-4ab2-b05f-13b47d042b85/