The GetYourGuide Ticketing WordPress plugin before 1.0.4 does not sanitise and escape some parameters, 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/b893cac2-6511-4e2a-9eff-baf0f3cc9d7e