---
id: "CVE-2026-84319"
kind: "vulnerability"
aliases: ["CVE-2026-84319", "GHSA-5r62-gj48-897x", "GO-2026-6774"]
title: "Nginx UI: MCP configuration tools bypass restricted directive validation and allow secondary authenticated users to execute NJS in Nginx worker context in github.com/0xJacky/Nginx-UI"
severity: "high"
cvss: 8.3
epss: 0.0028
exploited: false
status: "open"
category: "package"
products: [{"name": "github.com/0xJacky/Nginx-UI", "fixed": ["1.9.10-0.20260703131214-23d1934099b0"], "affected": "< 1.9.10-0.20260703131214-23d1934099b0", "ecosystem": "go"}]
ecosystems: ["go"]
tags: ["go", "nginx", "nginx-ui", "package", "self-hosted"]
not_affected_if: ["managed-hosting", "mcp-disabled", "single-admin-user"]
published_at: "2026-10-12T21:17:22+00:00"
first_seen_at: "2026-10-23T19:13:08+00:00"
updated_at: "2026-10-23T19:52:41+00:00"
sources: [{"source": "govuln", "url": "https://pkg.go.dev/vuln/GO-2026-6774", "first_seen_at": "2026-10-23T19:13:08+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-84319", "first_seen_at": "2026-10-23T19:13:43+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-84319", "first_seen_at": "2026-10-23T19:35:23+00:00"}]
---

# Nginx UI: MCP configuration tools bypass restricted directive validation and allow secondary authenticated users to execute NJS in Nginx worker context in github.com/0xJacky/Nginx-UI

Nginx UI, a web interface for managing Nginx, has an MCP configuration path that skips the directive checks the normal API enforces, so a secondary authenticated user can write restricted directives like load_module and js_content. That lets them run attacker-controlled NJS JavaScript inside the Nginx worker process after a reload.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- go:github.com/0xJacky/Nginx-UI affected < 1.9.10-0.20260703131214-23d1934099b0 fixed 1.9.10-0.20260703131214-23d1934099b0

## How to check

Check the Go module version of github.com/0xJacky/Nginx-UI in go.mod against the affected range below 1.9.10-0.20260703131214-23d1934099b0.

## Fix

Upgrade github.com/0xJacky/Nginx-UI to 1.9.10-0.20260703131214-23d1934099b0 or later; the description cites version 2.4.1 as the fix, which the sources do not reconcile with the Go module version.
Restrict Nginx UI user accounts to trusted users until patched.

## Timeline

- 2026-10-23T19:13:08+00:00 govuln https://pkg.go.dev/vuln/GO-2026-6774
- 2026-10-23T19:13:43+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2026-84319
- 2026-10-23T19:35:23+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-84319

## From the sources

Nginx UI is a web user interface for the Nginx web server. Prior to 2.4.1, the regular HTTP configuration API rejects restricted Nginx directives such as load_module, js_import, and js_content. However, the MCP configuration interface allows a secondary authenticated user to write and apply equivalent restricted configuration content. This allows the user to load ngx_http_js_module.so, import attacker-controlled JavaScript, reload Nginx, and execute NJS in the Nginx worker context. This issue is fixed in version 2.4.1.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_