Input validation vulnerability in Highlight 1.0.29

The Highlight theme for WordPress has a security issue that could put websites at risk. This issue affects versions 1.0.29 and below. It happens because the highlight_admin_ajax_welcome_notice_dismiss() function does not properly check for a special code, called a nonce, which helps prevent unauthorized actions. This means that someone without permission could trick a website administrator into doing something, like clicking on a link, and dismiss important notices.