# CVE-2026-84360: Nginx UI OTP secure-session step-up bypass via MCP

Source: https://junglewise.ai/threats/cve-2026-84360-nginx-ui-otp-secure-session-step-up-can-be-bypassed-via-mcp  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-12. Updated: 2026-10-15  
License: CC BY 4.0 with a link back

CVE-2026-84360 · Severity: high · CVSS 8.1 · Published 2026-10-12

Nginx UI is a web-based interface for managing Nginx web server configurations. An authenticated user with two-factor authentication (OTP) enabled can bypass the required step-up re-authentication and modify critical Nginx configurations by using the MCP (Model Context Protocol) endpoints instead of the standard HTTP API. This allows an attacker with compromised OTP-protected credentials to change web server settings without completing the intended second authentication check.

Technologies: [github.com/0xJacky/Nginx-UI (Go)](https://junglewise.ai/threats/technologies/github-com-0xjacky-nginx-ui), [Nginx UI](https://junglewise.ai/threats/technologies/nginx-ui-nginx-ui). Vendors: [Go](https://junglewise.ai/threats/vendors/go), [Nginx UI](https://junglewise.ai/threats/vendors/nginx-ui).

## Quick answers

**Is CVE-2026-84360 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-84360 being exploited in the wild.

**How severe is CVE-2026-84360?** High severity, with a CVSS score of 8.1, published 12 October 2026.

**Which products and versions are affected?** github.com/0xJacky/Nginx-UI (Go) < 1.9.10-0.20260703131214-23d1934099b0, SEMVER:introduced=0,fixed=1.9.10-0.20260703131214-23d1934099b0; Nginx UI <UNKNOWN>.

**Is there a fix for CVE-2026-84360?** Yes. github.com/0xJacky/Nginx-UI (Go): upgrade to 1.9.10-0.20260703131214-23d1934099b0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-84360 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-84360?** Check whether you run github.com/0xJacky/Nginx-UI (Go) or Nginx UI at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- github.com/0xJacky/Nginx-UI (Go): upgrade to 1.9.10-0.20260703131214-23d1934099b0 or later

  ```sh
  go get github.com/0xJacky/Nginx-UI@v1.9.10-0.20260703131214-23d1934099b0
  ```


## Technical details

The vulnerability is a security-control bypass in Nginx UI's authentication middleware. While HTTP configuration mutation endpoints require `middleware.RequireSecureSession()` to enforce OTP step-up, the MCP endpoints at `/mcp` and `/mcp_message` are protected only with `middleware.AuthRequired()`. The MCP server exposes configuration mutation tools (`nginx_config_add`, `nginx_config_modify`) that allow direct Nginx config changes, providing an unauthenticated bypass path around the secure session requirement for OTP-enabled users.

## Affected products

- Nginx UI Nginx UI <UNKNOWN>

## Identifiers

- CVE-2026-84360
- GHSA-vc32-4gwf-77xp
- GO-2026-6799

## Timeline

- 2026-10-15: disclosed

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- [Nginx UI auto backup path traversal in storage boundary](https://junglewise.ai/threats/cve-2026-84320-nginx-ui-auto-backup-name-allows-path-traversal-outside-validated)
- [Nginx UI MCP configuration directive validation bypass](https://junglewise.ai/threats/cve-2026-84319-nginx-ui-mcp-configuration-tools-bypass-restricted-directive)
- [nginx-ui MCP nginx_config_add directive validation bypass](https://junglewise.ai/threats/cve-2026-84318-nginx-ui-mcp-nginx-config-add-bypasses-directive-validation)