Blocks for ShopEngine < 2.4.4 - Contributor+ Stored XSS via gutenova_store_css

The ShopEngine Gutenberg WooCommerce Builder Blocks Addon WordPress plugin before 2.4.4 does not validate the user's capabilities or the ownership of the targeted post in one of its AJAX actions, and does not escape the stored value before outputting it in a JavaScript context, allowing users with a role as low as contributor to inject arbitrary scripts into any post that will run when a higher privileged user edits it.