The Herd Effects WordPress plugin before 5.2.3 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/c4ac0b19-58b1-4620-b3b7-fbe6dd6c8dd5