The Alemha watermarker WordPress plugin through 1.3.1 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/8c6f3e3e-3047-4446-a190-750a60c29fa3/