The Simple Side Tab WordPress plugin before 2.2.0 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/ff3f2788-d1a1-4a62-a247-39a931308f51/