The Formidable Forms WordPress plugin before 6.14.1 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/3c4ff11b-4a06-433d-8f0e-4069865721c0/