The Essential Addons for Elementor is a popular plugin for WordPress that adds extra features and designs to the Elementor page builder. However, it has a security vulnerability that allows hackers to insert harmful code into any page that uses the plugin. This can happen when someone with a certain level of access to the website (Contributor or higher) adds a specific text in a certain area of the plugin. This can be dangerous because it allows the hacker to run their code whenever someone visits the page they injected it into.