The Subscribe Forms WordPress plugin before 1.6.3 does not sanitise and escape one of its form...

The Subscribe Forms WordPress plugin before 1.6.3 does not sanitise and escape one of its form settings before outputting it in a page, allowing authenticated users with the Author role and above to perform Stored Cross-Site Scripting attacks that execute in the browser of any visitor who views a page embedding the form, including logged-out visitors and administrators.