NVD - CVE-2026-33032

3 min read Original article ↗

CVE-2026-33032 Detail

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.


Metrics

NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.

CVSS 4.0 Severity and Vector Strings:


NIST CVSS score

NIST: NVD

N/A

NVD assessment not yet provided.

CVSS 3.x Severity and Vector Strings:


NIST CVSS score

NIST: NVD

Base Score:  N/A

NVD assessment not yet provided.


Nist CVSS score does not match with CNA score

CNA:  GitHub, Inc.

Base Score:  9.8 CRITICAL

Vector:  CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS 2.0 Severity and Vector Strings:

National Institute of Standards and Technology

NIST: NVD

Base Score: N/A

NVD assessment not yet provided.

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
https://github.com/0xJacky/nginx-ui/security/advisories/GHSA-h6c2-x2m2-mwhf CISA-ADP, GitHub, Inc. Exploit  Mitigation  Vendor Advisory 
https://websec.net/blog/cve-2026-33032-unauthenticated-nginx-ui-mcp-takeover-69e1200f9fceb1f3fbe9c47f CVE

Weakness Enumeration

CWE-ID CWE Name Source
CWE-306 Missing Authentication for Critical Function GitHub, Inc.  

Known Affected Software Configurations Switch to CPE 2.2

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Change History

4 change records found show changes

CVE Modified by CVE 4/16/2026 6:16:37 PM

Action Type Old Value New Value
Added Reference
https://websec.net/blog/cve-2026-33032-unauthenticated-nginx-ui-mcp-takeover-69e1200f9fceb1f3fbe9c47f

Initial Analysis by NIST 4/01/2026 2:19:13 PM

Action Type Old Value New Value
Added CPE Configuration
OR
          *cpe:2.3:a:nginxui:nginx_ui:*:*:*:*:*:*:*:* versions up to (including) 2.3.5
Added Reference Type
CISA-ADP: https://github.com/0xJacky/nginx-ui/security/advisories/GHSA-h6c2-x2m2-mwhf Types: Exploit, Mitigation, Vendor Advisory
Added Reference Type
GitHub, Inc.: https://github.com/0xJacky/nginx-ui/security/advisories/GHSA-h6c2-x2m2-mwhf Types: Exploit, Mitigation, Vendor Advisory

CVE Modified by CISA-ADP 3/30/2026 3:16:25 PM

Action Type Old Value New Value
Added Reference
https://github.com/0xJacky/nginx-ui/security/advisories/GHSA-h6c2-x2m2-mwhf

New CVE Received from GitHub, Inc. 3/30/2026 2:16:19 PM

Action Type Old Value New Value
Added 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.
Added CVSS V3.1
AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Added CWE
CWE-306
Added Reference
https://github.com/0xJacky/nginx-ui/security/advisories/GHSA-h6c2-x2m2-mwhf

Quick Info

CVE Dictionary Entry:
CVE-2026-33032
NVD Published Date:
03/30/2026
NVD Last Modified:
04/16/2026
Source:
GitHub, Inc.