The AI Engine plugin for WordPress is vulnerable to a type of attack called Stored Cross-Site Scripting. This type of attack allows an attacker to inject malicious code into a website that will be executed whenever a user visits the website. This vulnerability is only present in versions up to 1.6.82 and only affects multi-site installations or installations where a specific security setting (unfiltered_html) has been disabled. To exploit this vulnerability, the attacker must have administrator-level permissions or higher.