Elementor Website Builder Pro <= 3.20.1 - Authententicated (Contributor+) Stored Cross-Site Scripting

The Elementor Website Builder Pro plugin for WordPress is vulnerable to Stored Cross-Site Scripting via widget's custom_id in all versions up to, and including, 3.20.1 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers with contributor-level and above permissions to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.