The Nested Pages WordPress plugin before 3.2.13 does not sanitise and escape some of its settings, which could allow high privilege users such as contributors to perform Stored Cross-Site Scripting attacks even when the unfiltered_html capability is disallowed (for example in multisite setup).
https://wpscan.com/vulnerability/69ddd8eb-33f1-49cf-9428-3d89262b1887/