The tourmaster WordPress plugin before 5.4.8 does not perform a nonce check when storing a custom-filter label taken from a request paramete

The tourmaster WordPress plugin before 5.4.8 does not perform a nonce check when storing a custom-filter label taken from a request parameter, and does not escape that label when echoing it on the filter admin page, allowing an unauthenticated attacker to trick a logged-in administrator into storing JavaScript that then executes in the admin area (stored Cross-Site Scripting via CSRF).