Nginx UI: MCP configuration tools bypass restricted directive validation and allow secondary authenticated users to execute NJS in Nginx worker context
CVSS score
8.3
EPSS probability
—
Risk score
0.8
Published
7 h ago
Resmî kaynaklarda yeterli kanıt bulunamadı. Bu sonuç “yama yok” anlamına gelmez.
Impact on My Inventory
Only the personal products you have added to your account are assessed; an organisation's inventory does not appear here.
Checking session…
Vulnerability description
CVE AI research
DayBreach AI Explanation
Verified against sourcesSources read
1
Source agreement
Tam uyum
Evidence confidence
%55
Short explanation
Prior to Nginx UI version 2.4.1, the MCP configuration interface allows a secondary authenticated user to write and apply restricted configuration content. This enables NJS execution within the Nginx worker context.
It matters because it allows an authenticated secondary user to apply restricted Nginx directives and execute code within the worker context, presenting a high risk.
What should be done?
- Upgrade to version 2.4.1 or later
- Follow vendor advisories
Chain of evidence and sources
Normal HTTP yapılandırma API'si kısıtlanmış yönergeleri reddederken MCP arayüzü bunların yazılmasına izin verir.
Bu güvenlik açığı Nginx UI sürüm 2.4.1'de giderilmiştir.
Show the technical text 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.
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:H
CWE: CWE-693
Explanation produced with the local gemini-flash-lite-latest model. Numerical metrics and the KEV, patch and exploit statuses are not determined by AI.
IMPACT: Affected Products and Software
Affected Products
The following products are affected by CVE-2026-84319 vulnerability. Where our threat engine knows the exact affected versions, they are listed below.
| ID | VENDOR | PRODUCT | ACTION |
|---|---|---|---|
| 1 | 0xJacky | nginx-ui | View |
RED HAT CSAF/VEX: Product Impact Check
SCORING: CVSS from Multiple Sources
CVSS Scores
The Common Vulnerability Scoring System is a standardised framework for assessing the severity of vulnerabilities in software and systems. We collect and display CVSS scores from several sources for each CVE.
| SCORE | VERSION | SEVERITY | VECTOR | SOURCE |
|---|---|---|---|---|
| 8.3 | CVSS V31 | HIGH | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:H | NVD |
| 8.3 | CVSS V3_1 | HIGH | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:H | CVE CNA |
Patch and Remediation Guide
Solution & Remediation Advisory
İncelenen resmî kaynaklarda yama durumu doğrulanamadı. Bu sonuç “yama yok” anlamına gelmez.
Public exploit and active exploitation status
Verified exploit intelligence
No verified public PoC, exploit repository or Metasploit module has been found for this CVE yet.
Weakness Classification and Attack Patterns (CWE & CAPEC)
CWE - Common Weakness Enumeration
While CVE identifies specific instances of vulnerabilities, CWE categorises the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-84319 is associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-84319 weaknesses.
Attack Vector and Accessibility
Official Sources and Advisories
Similar Vulnerabilities
Nginx UI: nginx config directive denylist (ValidateConfigFile) is bypassable via same-line ";" separation → authenticated directive injection (RCE on the official image)
Nginx UI: MCP nginx_config_add skips config directive validation → authenticated nginx directive injection (RCE on the official image)
Nginx UI: TOTP / passkey enrolment requires no re-authentication, enabling persistent account takeover
Nginx UI: MCP `nginx_config_add` Bypasses Directive Validation — Authenticated RCE
Nginx UI: Account Takeover via Missing `RequireSecureSession` on User Management Endpoint
Nginx UI OTP secure-session step-up is missing on sensitive mutation routes
Get this vulnerability through the API
Affected products, version ranges, exploitation status and patch information in a single request, with a free key.
curl -H "x-api-key: $DAYBREACH_API_KEY" \ "https://api.enginteksut.com.tr/api/v1/intel/cves/CVE-2026-84319"