Vulnerability in github.com/0xJacky/Nginx-UI (CVE-2026-84319)
Summary
Vulnerability in github.com/0xJacky/Nginx-UI (CVE-2026-84319). Data can be tampered with by attackers. Exploitable via POST /api/configs. Mitigation: upgrade to 1.9.10-0.20260703131214-23d1934099b0 or later.
Original description
The description as published by the source.
Summary
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. In the lab, this allowed the user to load ngx_http_js_module.so, import attacker-controlled JavaScript, reload Nginx, and execute NJS in the Nginx worker context.
This is authenticated and is not OS command execution by itself.
Affected component
/mcp/mcp_message- MCP tool:
nginx_config_add - Nginx configuration validation
Impact
A secondary authenticated user can bypass the restricted directive validation enforced by the HTTP API and execute attacker-controlled NJS inside the Nginx worker context.
This may allow modification of Nginx runtime behavior, including responses, routing, headers, redirects, and request handling.
Minimal PoC
Preconditions
- Attacker has a secondary authenticated Nginx UI account.
- MCP is enabled.
- Nginx has NJS available:
find / -name "ngx_http_js_module.so" 2>/dev/null
Observed in the lab:
/usr/lib/nginx/modules/ngx_http_js_module.so
1. HTTP API blocks the restricted config
Request:
POST /api/configs
Authorization:
Content-Type: application/json
Body:
{
"name": "nginx.conf",
"base_dir": "",
"overwrite": true,
"sync_node_ids": [],
"content": "load_module modules/ngx_http_js_m…
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-84319 has been found in github.com/0xJacky/Nginx-UI.
Attackers can target a specific entry point like POST /api/configs over the network to misuse the product.
Data can be tampered with by attackers. CVSS score: 8.3/10.
What to do: upgrade github.com/0xJacky/Nginx-UI to 1.9.10-0.20260703131214-23d1934099b0 or later.
If unsure, ask your IT team or search "github.com/0xJacky/Nginx-UI CVE-2026-84319" on the vendor's site.
CVE-2026-84319 (github.com/0xJacky/Nginx-UI) — CWE-693 / CVSS v3 8.3
Attack vector: remote (network-reachable) / no user interaction
Attack surface: POST /api/configs / load_module / js_import / js_content
Patched: 1.9.10-0.20260703131214-23d1934099b0 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-693) exists in github.com/0xJacky/Nginx-UI. Attackers reach the vulnerable code path via POST /api/configs.
Check the vendor advisory for the affected versions of github.com/0xJacky/Nginx-UI. Attack surface: POST /api/configs / load_module / js_import / js_content.
Severity: High (CVSS 8.3/10). Data can be tampered with by attackers.
Update to 1.9.10-0.20260703131214-23d1934099b0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual POST /api/configs requests with malformed payloads or SQL meta-characters. Run grep -r 'github.com/0xJacky/Nginx-UI' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'github.com/0xJacky/Nginx-UI' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
github.com/0xJacky/Nginx-UIを grep し、稼働しているサービス・バージョンを把握する。 -
2Hunt for indicators of compromise detect
grep 'POST /api/configs' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで
POST /api/configsへの異常なリクエスト (不正な認証ヘッダ・SQLメタ文字)を過去 30〜90日分捜索。WAF/SIEM があれば該当パスのアラート発火履歴を確認。 -
3Apply patch patch
Upgrade github.com/0xJacky/Nginx-UI to 1.9.10-0.20260703131214-23d1934099b0ステージング環境で 1.9.10-0.20260703131214-23d1934099b0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスと、Step 2 で見つけた異常検知の続報チェックを含めること。
-
4Post-deployment verification verify
Replay attack against POST /api/configs on staging to confirm patch closes the vectorパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番では Step 2 と同じログクエリでアラート再発が無いか継続監視。
Affected packages
References
- advisory nvd.nist.gov
- package github.com
- web github.com
- web github.com
- web github.com
- web github.com