CVE-2026-84317 · GHSA-76pm-mq2q-9gcr
Nginx UI: MCP nginx_config_add skips config directive validation → authenticated nginx directive injection (RCE on the official image)
- Risk score
- 76/100
- CVSS
- 8.8 v3.1
- Exploit chance (30 days)
- 0.5%
- Published
- 12 Oct 2026
Open in the live forecast Today's forecast
What to know
- What it is
- Nginx UI is a web user interface for the Nginx web server. Prior to 2.4.1, internal/config/validation.go (ValidateConfigFile) is a security control that blocks dangerous nginx directives — js_*, perl_*, load_module of the njs/perl modules, and user root. It is enforced on three of the four config-write paths: api/conf…
- Affected
- github.com/0xJacky/Nginx-UI (go) < 1.9.10-0.20260703131214-23d1934099b0
- Fix
- Upgrade github.com/0xJacky/Nginx-UI to 1.9.10-0.20260703131214-23d1934099b0 or later.
- Exploitation
- Public proof of concept
Story map
At a glance
github.com/0xJacky/Nginx-UI: Amber, patch this week. Nginx UI is a web user interface for the Nginx web server. Prior to 2.4.1, config.ValidateConfigDirectives splits configuration by newline and checks only the first directive token on each line even though Nginx permits multiple semicolon-separated directives on one line. An authenticated caller can place a benign dir…
The flaws
- CVE-2026-84317: Nginx UI: MCP nginx_config_add skips config directive validation → authenticated nginx directive injection (RCE on the official image) (CVSS 8.8 · EPSS 0%)
- CVE-2026-84316: Nginx UI: nginx config directive denylist (ValidateConfigFile) is bypassable via same-line ";" separation → authenticated directive injection (RCE on the official image) (CVSS 8.8 · EPSS 1%)
- CVE-2026-84318: Nginx UI: MCP `nginx_config_add` Bypasses Directive Validation — Authenticated RCE (CVSS 8.8 · EPSS 1%)
- CVE-2026-84314: Nginx UI: Account Takeover via Missing `RequireSecureSession` on User Management Endpoint (CVSS 8.7 · EPSS 0%)
The fix
Upgrade github.com/0xJacky/Nginx-UI: 2.4.1 or later on your release line
Who is exposed: github.com/0xJacky/Nginx-UI (go) < 1.9.10-0.20260703131214-23d1934099b0
Where it stands
- Public proof of concept
Connects to
- Same weakness: CWE-693 (CWE-693). 59 other warnings in 30 days
Why it is Amber
- CVSS 8.8 high
- Public exploit or proof of concept referenced
- On your watchlist: nginx, Go
Affected packages
| Package | Ecosystem | Vulnerable | Fixed in |
|---|---|---|---|
| github.com/0xJacky/Nginx-UI | go | < 1.9.10-0.20260703131214-23d1934099b0 | 1.9.10-0.20260703131214-23d1934099b0 |
References
- https://github.com/advisories/GHSA-76pm-mq2q-9gcr
- https://github.com/0xJacky/nginx-ui/security/advisories/GHSA-76pm-mq2q-9gcr
- https://nvd.nist.gov/vuln/detail/CVE-2026-84317
- https://github.com/0xJacky/nginx-ui/commit/23d1934099b05b2a01589b48129dc3d3159d91c2
- https://github.com/0xJacky/nginx-ui/releases/tag/v2.4.1
- https://github.com/advisories/GHSA-76pm-mq2q-9gcr
Original description
Nginx UI is a web user interface for the Nginx web server. Prior to 2.4.1, internal/config/validation.go (ValidateConfigFile) is a security control that blocks dangerous nginx directives — js_*, perl_*, load_module of the njs/perl modules, and user root. It is enforced on three of the four config-write paths: api/config/add.go, api/config/modify.go, and mcp/config/config_modify.go. The fourth path — the MCP tool nginx_config_add (mcp/config/config_add.go) — does NOT call it: it writes the caller-supplied content straight to disk and reloads nginx. An authenticated MCP caller (or an MCP agent induced via prompt injection) can therefore inject exactly the directives the control is meant to block, leading to nginx code execution on deployments where the njs/perl module is available (e.g. the official Docker image). This issue is fixed in version 2.4.1.
Last activity 12 Oct 2026. Patch Forecast updates every hour.