The WP Discord Invite WordPress plugin before 2.5.2 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/564ad2b0-6ba6-4415-98d7-8d41bc1c3d44