CVE-2026-33032
In versions 2.3.5 and prior, the nginx-ui MCP (Model Context Protocol) integration exposes two HTTP endpoints: /mcp and /mcp_message.
Does this matter?
EPSS puts the probability of exploitation in the next 30 days at 35.3%, higher than 98% of all known CVEs. Patch or mitigate before the next change window.
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 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 35.27% probability · 98th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-306
- Affected
- nginxui/nginx ui
- Source
- security-advisories@github.com
EPSS moved from 2.5% on 24 September 2026 to 35.3% on 30 October 2026. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”.
References
- https://github.com/0xJacky/nginx-ui/security/advisories/GHSA-h6c2-x2m2-mwhfExploit, Mitigation, Vendor Advisory
- https://websec.net/blog/cve-2026-33032-unauthenticated-nginx-ui-mcp-takeover-69e1200f9fceb1f3fbe9c47f
- https://github.com/0xJacky/nginx-ui/security/advisories/GHSA-h6c2-x2m2-mwhfExploit, Mitigation, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.