The Popup Maker – Boost Sales, Conversions, Optins, Subscribers with the Ultimate WP Popups Builder plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the ‘close_text’ parameter in all versions up to, and including, 1.19.0 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.