The AI Engine plugin for WordPress is vulnerable to open redirect in version 2.8.4. This is due to an insecure OAuth implementation, as the 'redirecturi' parameter is missing validation during the authorization flow. This makes it possible for unauthenticated attackers to intercept the authorization code and obtain an access token by redirecting the user to an attacker-controlled URI. Note: OAuth is disabled, the 'MeowMWAILabsOAuth' class is not loaded in the plugin in the patched version 2.8.5.