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

Exp

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.

Published: 2026-03-30 Last update: 2026-04-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-33032 is rated High Exploit Risk (90.1/100): CVSS Critical severity, with high exploitation likelihood (EPSS 15.42%, 95th percentile). 1 public exploit reference(s) are indexed (Exploit-DB). EPSS rose +2.75% over the last day, indicating growing attacker interest. Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2026-33032

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2026-33032

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-05 12.67% 15.42% +2.75%
2 2026-06-03 13.25% 12.67% -0.58%
3 2026-05-28 — 13.25% —

Full EPSS history (15 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-33032

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]

Weakness enumeration for CVE-2026-33032

GitHub Security Advisory for CVE-2026-33032

GHSA-h6c2-x2m2-mwhf · Severity: critical · Ecosystem: go — nginx-ui's Unauthenticated MCP Endpoint Allows Remote Nginx Takeover

Affected software / configurations for CVE-2026-33032

Vendor Product Version Raw CPE
nginxui nginx_ui <= 2.3.5 cpe:2.3:a:nginxui:nginx_ui:*:*:*:*:*:*:*:*

References for CVE-2026-33032

cvelogic Threat Intelligence