Colibri Page Builder <= 1.0.334 - Authenticated (Contributor+) Stored Cross-Site Scripting via colibri_newsletter Shortcode

The Colibri Page Builder plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's colibri_newsletter shortcode in all versions up to, and including, 1.0.334 due to insufficient input sanitization and output escaping on user supplied attributes. 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.