AI Engine – MCP Server & AI Chatbot for WordPress, with Claude, ChatGPT & Gemini <= 3.9.3 - Unauthenticated Stored Cross-Site Scripting via File Upload
- ID
- WPSEC-2026-3047
- Plugin
- AI Engine – MCP Server & AI Chatbot for WordPress, with Claude, ChatGPT & Gemini (ai-engine)
- Affected
- all versions before 3.9.4
- Remediation
- Update to 3.9.4 or later.
- CVSS 3.1
- CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
- Weakness
- CWE-79
- Usage
- Plugin Low · Affected versions Low among sites WPSec scans, 2026-11-13
- Attack surface
- AI Engine – MCP Server & AI Chatbot for WordPress, with Claude, ChatGPT & Gemini on WPSec AttackSurface
- Fix released
- Published
Description
The AI Engine plugin for WordPress is vulnerable to Stored Cross-Site Scripting via file uploads (the chatbot and AI Forms upload endpoint /mwai-ui/v1/files/upload) in all versions up to, and including, 3.9.3, due to insufficient validation of uploaded file types and contents. The endpoint is open to visitors through a publicly exposed nonce and accepts any file type WordPress allows, including text-based types such as .rtx (text/richtext) that many web servers send without a Content-Type, so a file starting with HTML markup is rendered as a web page by browsers. This makes it possible for unauthenticated attackers to store files in the public uploads folder that run arbitrary web scripts when a user opens them.
References
- https://wpsec.com/vuln/WPSEC-2026-3047/
- https://plugins.svn.wordpress.org/ai-engine/tags/3.9.4/
- https://wordpress.org/plugins/ai-engine/
Published by WPSec. Provided as is, without warranty. Corrections: contact us.
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