The WP GDPR Cookie Consent plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'ninja_gdpr_ajax_actions' AJAX action in versions up to, and including, 1.0.0. This is due to missing capability and nonce checks on the handleAjaxCalls() function, combined with insufficient input sanitization on the gdprConfig values and missing output escaping in the generateCSS() function which echoes stored configuration values directly into a <style> block rendered on wp_head. This makes it possible for authenticated attackers, with subscriber-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.