The Nested Pages WordPress plugin before 3.2.9 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/3dd41ecb-d0dc-4c23-9e5b-b1f7fbaaddfd/