YaySMTP < 2.2.2 - Admin+ Stored Cross-Site Scripting

The plugin 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 when the unfiltered_html capability is disallowed (for example in multisite setup)

PoC

Put the following payload in the From Email or From Name settings and save them: " autofocus onfocus=alert(/XSS/)//