What’s Vulnerable › Vulnerabilities

CVE-2026-33032: Nginx UI: Unauthenticated MCP Endpoint Allows Remote Nginx Takeover

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 35.3% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-03-30 · updated 2026-06-17
• Weakness: CWE-306

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.

Affected products

• 0xJacky nginx-ui: through 2.3.5

References

• https://github.com/0xJacky/nginx-ui/security/advisories/GHSA-h6c2-x2m2-mwhf
• https://websec.net/blog/cve-2026-33032-unauthenticated-nginx-ui-mcp-takeover-69e1200f9fceb1f3fbe9c47f
• https://github.com/0xJacky/nginx-ui/security/advisories/GHSA-h6c2-x2m2-mwhf

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