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

> Unauthenticated access to the MCP endpoint allows remote attackers to modify Nginx configurations and restart the service, leading to full service takeover.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 30 Mar 2026
- **Updated:** 16 Apr 2026
- **Also known as:** GHSA-h6c2-x2m2-mwhf, GO-2026-4904

## What is CVE-2026-33032?

CVE-2026-33032 is a critical missing authorization vulnerability in 0xJacky nginx-ui, published on 30 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-306 (Missing Authentication for Critical Functionality)

## Which versions are affected by CVE-2026-33032?

3 open source packages ship an affected version, including github.com/0xJacky/Nginx-UI. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/0xJacky/Nginx-UI` | Go | All versions | None |
| `github.com/0xJacky/Nginx-UI` | Go | All versions to 1.99 | None |
| `github.com/0xJacky/Nginx-UI` | Go | All versions to 1.99 | None |

Products: Nginxui Nginx Ui.

## How do I fix CVE-2026-33032?

No fix published yet.

## Is CVE-2026-33032 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-33032 exists.

Public exploit code:

- One missing function call on the route registration was enough to turn the MCP interface into an unauthenticated RCE gateway. (github_poc): https://github.com/keraattin/CVE-2026-33032
- Non-destructive vulnerability scanner for Nginx-UI MCP Endpoint Authentication Bypass (CVE-2026-33032) (github_poc): https://github.com/Twinson333/cve-2026-33032-scanner
- Docker Compose setup to demonstrate the nginx-ui missing authentication vulnerability (github_poc): https://github.com/Shreda/CVE-2026-33032-nginx-ui-vuln-lab
- https://github.com/Baba01hacker666/CVE-2026-33032 (github_poc): https://github.com/Baba01hacker666/CVE-2026-33032
- Nginx UI - Broken Access Control (nuclei): http/cves/2026/CVE-2026-33032.yaml

## Other vulnerabilities in 0xJacky nginx-ui

- [CVE-2026-27944](https://insights.sbomify.com/CVE-2026-27944/): Nginx UI: Unauthenticated Backup Download with Encryption Key Disclosure (critical 9.8)
- [CVE-2024-23827](https://insights.sbomify.com/CVE-2024-23827/): Nginx-UI arbitrary file write through the Import Certificate feature (critical 9.8)
- [CVE-2026-107806](https://insights.sbomify.com/CVE-2026-107806/): Nginx UI: Authenticated Remote Code Execution via Backup Restore App Config Overwrite (critical 9.4)
- [CVE-2026-33026](https://insights.sbomify.com/CVE-2026-33026/): nginx-ui Backup Restore Allows Tampering with Encrypted Backups (critical 9.4)
- [CVE-2026-42238](https://insights.sbomify.com/CVE-2026-42238/): Unauthenticated Remote Code Execution via Backup Restore in nginx-ui (critical 9.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-33032 and fix it if it is affected.

What it is: CVE-2026-33032 is a critical missing authorization vulnerability in 0xJacky nginx-ui, published on 30 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-33032 exists.

Affected packages and fixed versions:
- github.com/0xJacky/Nginx-UI (Go): affected all versions; no fix listed
- github.com/0xJacky/Nginx-UI (Go): affected all versions up to 1.99; no fix listed
- github.com/0xJacky/Nginx-UI (Go): affected all versions up to 1.99; no fix listed

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-33032/ (Markdown: https://insights.sbomify.com/CVE-2026-33032/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-33032
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-33032
- OSV: https://osv.dev/vulnerability/CVE-2026-33032

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-33032/
Summaries are generated and may contain mistakes; the official description above is the record.