The Header Footer Builder for Elementor WordPress plugin before 1.2.1 does not require an administrative capability for its dashboard template-import action (it allows any edit_posts user), so a Contributor can import a template containing an Elementor HTML widget configured to display site-wide, injecting JavaScript that executes in the session of any visitor or administrator who loads the site.
https://wpscan.com/vulnerability/3c6562d9-f55e-4d82-be95-60e82a6feecf/