Volunteer Sign Up Sheets <= 5.5.4 - Authenticated (Admin+) Stored Cross-site Scripting

The Volunteer Sign Up Sheets plugin for WordPress is vulnerable to Stored Cross-Site Scripting via admin settings in all versions up to, and including, 5.5.4 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with administrator-level permissions and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This only affects multi-site installations and installations where unfiltered_html has been disabled. Please note the patched version is only available from the plugin author's Github Repository: https://github.com/dbarproductions/pta-volunteer-sign-up-sheets/tags.