The AI Engine plugin for WordPress (tigroumeow) suffers from a stored cross-site scripting vulnerability (CWE-79) via the mwai_chatbot shortcode 'id' parameter. This parameter is not properly sanitized or escaped, allowing authenticated users with at least Subscriber privileges to inject arbitrary JavaScript code. When other users access the pages containing the injected code, the scripts execute in their browsers. The vulnerability affects all plugin versions up to 2.8.4. The CVSS 3.1 base score is 5.4, reflecting network attack vector, low attack complexity, required privileges at the Subscriber level, user interaction needed, and impacts on confidentiality and integrity but not availability.

An attacker with Subscriber-level access or higher can inject malicious scripts that execute in the context of other users viewing the affected pages, potentially leading to session hijacking, data theft, or other client-side attacks. The impact is limited to confidentiality and integrity with no direct availability impact. Since the vulnerability requires authenticated access and user interaction, the risk is moderate.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, restrict Subscriber-level user capabilities where possible and monitor for suspicious shortcode usage. Avoid granting unnecessary privileges to untrusted users. Follow vendor updates closely for patches or official mitigations.