The WPeMatico RSS Feed Fetcher WordPress plugin before 2.8.26 does not sanitise and escape one of its campaign configuration fields when a certain feature is enabled, which allows users with the Contributor role and above to perform Stored Cross-Site Scripting attacks that execute in the session of any higher-privileged user who later views the campaign.
https://wpscan.com/vulnerability/1c6f4da0-d7e8-4f50-851f-f794552db985/