The Responsive Contact Form Builder & Lead Generation Plugin WordPress plugin before 1.9.8 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/faca59fb-6b59-45b0-8b97-c4125d9d3cb3/