The Duplicate Page WordPress plugin through 4.4.2 does not sanitise or escape the Duplicate Post Suffix settings before outputting it, which could allow high privilege users to perform Stored Cross-Site Scripting attacks even when the unfiltered_html capability is disallowed.
https://wpscan.com/vulnerability/9ebdd1df-1d6f-4399-8b0f-77a79f841464