The Salon booking system WordPress plugin through 9.6.5 does not sanitise and escape some of its settings, which could allow high privilege users such as Editor to perform Stored Cross-Site Scripting attacks even when the unfiltered_html capability is disallowed (for example in multisite setup)
https://wpscan.com/vulnerability/7a375077-fc70-4389-b109-28fce3db2aef/