by Kastro
Paper/Archive/CVE-2026-33032

CVE-2026-33032

0xJacky nginx-ui — Nginx UI: Unauthenticated MCP Endpoint Allows Remote Nginx Takeover

EPSS 35%public exploitCVSS 9.8
critical.is priorityof 100
59
CVSS 9.8 (CNA)9.8 / 10 × 3029.4Not in CISA KEV+300.0EPSS percentile 98.4.984 × 2019.7Exploit: SSVC poc+1010.0SSVC exploitation: poc+100.0
Description · from the CVE record

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

ProductAffectedFixed inSource
nginx-ui<= 2.3.5–CNA

Scores by source

GitHub_M (CNA)9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CISA ADPSSVCExploitation: poc · Automatable: yes · Technical impact: total

References

exploitgithub.com/0xJacky/nginx-ui/security/advisories/GHSA-h6c2-x2m2-mwhfrefwebsec.net/blog/cve-2026-33032-unauthenticated-nginx-ui-mcp-takeover-69e1200f9fceb1f3fbe9c47f