The Email Customizer for WooCommerce plugin for WordPress is vulnerable to Stored Cross-Site Scripting via email template content in all versions up to, and including, 2.6.7 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with administrator-level access, to inject arbitrary web scripts in email templates that will execute when customers view transactional emails. This only affects multi-site installations and installations where unfiltered_html has been disabled.
