The Hostel WordPress plugin before 1.1.5.9 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/ff4d312b-a4d1-40cd-a555-a0a1b46f9959/