Vulnerability Description
Nginx UI is a web user interface for the Nginx web server. In versions 2.3.5 and prior, the nginx-ui MCP (Model Context Protocol) integration exposes two HTTP endpoints: /mcp and /mcp_message. While /mcp requires both IP whitelisting and authentication (AuthRequired() middleware), the /mcp_message endpoint only applies IP whitelisting - and the default IP whitelist is empty, which the middleware treats as "allow all". This means any network attacker can invoke all MCP tools without authentication, including restarting nginx, creating/modifying/deleting nginx configuration files, and triggering automatic config reloads - achieving complete nginx service takeover. At time of publication, there are no publicly available patches.
CVSS Score
CRITICAL
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Nginxui | Nginx Ui | <= 2.3.5 |
Related Weaknesses (CWE)
References
- https://github.com/0xJacky/nginx-ui/security/advisories/GHSA-h6c2-x2m2-mwhfExploitMitigationVendor Advisory
- https://websec.net/blog/cve-2026-33032-unauthenticated-nginx-ui-mcp-takeover-69e
- https://github.com/0xJacky/nginx-ui/security/advisories/GHSA-h6c2-x2m2-mwhfExploitMitigationVendor Advisory
FAQ
What is CVE-2026-33032?
CVE-2026-33032 is a vulnerability with a CVSS score of 9.8 (CRITICAL). Nginx UI is a web user interface for the Nginx web server. In versions 2.3.5 and prior, the nginx-ui MCP (Model Context Protocol) integration exposes two HTTP endpoints: /mcp and /mcp_message. While /...
How severe is CVE-2026-33032?
CVE-2026-33032 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-33032?
Check the references section above for vendor advisories and patch information. Affected products include: Nginxui Nginx Ui.