Introduction
On a WordPress site running AI Engine plugin versions 2.9.3 or 2.9.4, a single subscriber account can upload arbitrary files to the server, which may lead to remote code execution. The flaw (CVE-2025-7847, CVSS 8.8) is rated high severity, is trivial to exploit, and affects over 100,000 active installations. That makes it a significant risk for organizations that rely on AI-driven WordPress features.
About AI Engine: AI Engine is a widely adopted WordPress plugin that adds AI-powered chatbots, content generation, and automation to a site. It runs on over 100,000 active sites and is one of the main ways WordPress-based businesses and content creators add AI capabilities.
Technical information
The vulnerability is in the rest_simpleFileUpload function in AI Engine plugin versions 2.9.3 and 2.9.4. The function is reachable through the REST API endpoint /wp-json/mwai-ui/v1/files/upload, and it does not validate file type or extension. Any authenticated user with subscriber-level access or higher can therefore upload arbitrary files, including executable PHP scripts.
Key technical points:
- WordPress enables the REST API by default, so most installations are exposed unless someone has specifically hardened them.
- The vulnerable code is publicly visible in the plugin's repository (api.php#L673, files.php#L332).
- An attacker authenticates as a subscriber, then POSTs a malicious file to the REST endpoint. The server accepts and stores the file without restriction.
- If the uploaded file is a PHP script and the uploads directory allows execution, the attacker can achieve remote code execution by requesting the file over HTTP.
- The flaw maps to CWE-434 (Unrestricted Upload of File with Dangerous Type).
Vulnerable code reference:
Detection methods
Five checks can reveal exploitation of the arbitrary file upload vulnerability in the AI Engine WordPress plugin.
1. Monitor web server logs
Review your logs regularly for unusual POST requests to /wp-json/mwai-ui/v1/files/upload. Unauthorized or unexpected requests to this endpoint may indicate exploitation attempts. (patchstack.com)
2. Inspect uploaded files
Check your WordPress uploads directory (/wp-content/uploads/) for files with suspicious extensions such as .php, which standard media functions do not normally upload. A file like that could signify a successful exploit. (patchstack.com)
3. Use security plugins
Plugins such as Wordfence can detect and block malicious file uploads. They monitor for known attack patterns, send real-time alerts, and can prevent unauthorized access. (wordfence.com)
4. Implement file integrity monitoring
A file integrity monitoring system detects unauthorized changes or additions to your site's files, and its alerts can show when someone has uploaded a malicious file.
5. Review user accounts and permissions
Audit user accounts and their permissions regularly, with particular attention to users at Editor level and above. Give upload capability only to people you trust, which reduces the risk of internal exploitation. (wordfence.com)
Affected systems and versions
- AI Engine WordPress plugin versions 2.9.3 and 2.9.4 are directly affected
- The vulnerability is present when the REST API is enabled (default in WordPress)
- Sites running version 2.9.5 or later are not affected
Vendor security history
AI Engine has had at least five vulnerabilities in 2025, including arbitrary file upload and privilege escalation issues. The vendor has released patches quickly, usually within days of disclosure, but the number of critical issues points to recurring security problems in its development lifecycle.
