Vulnerability in 9router (CVE-2026-49353)
Summary
Vulnerability in 9router (CVE-2026-49353). Data can be tampered with by attackers. Exploitable via GET /api/mcp/.
Original description
The description as published by the source.
9Router is an AI router & token saver. In 0.4.45 and earlier, 9Router's src/dashboardGuard.js local-only access gate used Host and Origin headers in isLocalRequest() to protect /api/mcp/, /api/tunnel/, and /api/cli-tools/*, allowing header spoofing in reverse proxy or tunnel deployments to reach MCP child process stdin paths.
Source: GitHub Security Advisories (Global) 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-2026-49353 has been found in 9router.
Attackers can target a specific entry point like GET /api/mcp/ over the network to misuse the product.
Data can be tampered with by attackers. CVSS score: 7.5/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "9router CVE-2026-49353" on the vendor's site.
CVE-2026-49353 (9router) — CWE-290 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: GET /api/mcp/ / POST /api/mcp/ / GET /api/mcp/browser/sse / Host
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-290) exists in 9router. Attackers reach the vulnerable code path via GET /api/mcp/ without authentication.
Check the vendor advisory for the affected versions of 9router. Attack surface: GET /api/mcp/ / POST /api/mcp/ / GET /api/mcp/browser/sse / Host.
Severity: High (CVSS 7.5/10). Data can be tampered with by attackers.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual GET /api/mcp/ requests with malformed payloads or SQL meta-characters. Run grep -r '9router' . 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 '9router' . | 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
9router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 'GET /api/mcp/' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで
GET /api/mcp/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。 -
3Post-deployment verification verify
Replay attack against GET /api/mcp/ 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 github.com
- advisory github.com
- advisory nvd.nist.gov
- package github.com
- patch github.com
- patch github.com
- web github.com
- web github.com