The Advanced Cron Manager WordPress plugin before 2.5.7 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/8e5e7040-b824-4af7-90a1-90801d12abb6/