Executive brief
9Router, an AI-powered router and token management tool, contains a security flaw in how it verifies local access. The system attempts to restrict sensitive administrative and plugin interfaces to local users only, but it relies on easily faked web headers rather than actual network addresses. If the router is used behind a proxy or tunnel, an attacker can bypass these restrictions to interact with internal processes, potentially leading to unauthorized command execution on the host machine.
Technical details
The vulnerability exists in the isLocalRequest() function within src/dashboardGuard.js, which validates 'local' requests by checking if the Host and Origin headers match loopback addresses (e.g., localhost, 127.0.0.1). Because these headers are attacker-controlled when the application is deployed behind a reverse proxy or tunnel (such as Cloudflare Tunnel or Tailscale), the local-only gate can be bypassed. While a second factor (CLI token) is required, this token is a deterministic HMAC of the machine ID, which may be predictable in cloud environments. Successful exploitation allows an attacker to reach /api/mcp/* and other sensitive routes, enabling interaction with child process stdin (node, python, etc.) and potentially achieving Remote Code Execution (RCE). This is an incomplete fix for a previous vulnerability (CVE-2026-46339).
Affected products
- decolua 9router <= 0.4.55
Timeline
- 2026-05-15: patched: Version 0.4.46 released with initial hardening.
- 2026-06-13: advisory: GHSA-6g2f-w7g3-77vf published detailing the incomplete fix.
- 2026-07-15: disclosed: CVE-2026-49353 published to NVD.