CVE-2026-59801: 9Router Auth Bypass Vulnerability

CVE-2026-59801 Overview

CVE-2026-59801 is a missing authentication vulnerability [CWE-306] affecting 9Router through version 0.4.41. The Next.js API routes under src/app/api/providers/* lack authentication middleware, allowing unauthenticated remote attackers to interact with provider management endpoints. Attackers can enumerate, create, modify, or delete provider connections without any credentials. Successful exploitation exposes partial credentials, OAuth tokens, and API keys, enables redirection of AI traffic to attacker-controlled servers, and permits complete denial of service through deletion of all provider connections.

Critical Impact
Unauthenticated network attackers can steal AI provider credentials, hijack model traffic, and delete configuration data on any exposed 9Router instance.

Affected Products

9Router versions through 0.4.41
Next.js API routes under src/app/api/providers/*
Deployments exposing the 9Router management interface to untrusted networks

Discovery Timeline

2026-07-13 - CVE-2026-59801 published to NVD
2026-07-14 - Last updated in NVD database

Technical Details for CVE-2026-59801

Vulnerability Analysis

9Router exposes provider management functionality through Next.js API routes under src/app/api/providers/*. These routes handle create, read, update, and delete operations for AI provider connections. The routes ship without any authentication middleware, so the server treats every request as authorized.

An unauthenticated attacker who can reach the HTTP interface can enumerate configured providers and retrieve response bodies containing partial API keys, OAuth tokens, and provider metadata. The same endpoints accept write operations, letting the attacker create new provider entries or overwrite existing ones with endpoints under their control. Because 9Router routes AI traffic through these providers, redirection lets the attacker intercept prompts, responses, and any embedded secrets. Deleting all provider connections through the DELETE handlers produces a complete denial of service for the router.

Root Cause

The root cause is missing authentication [CWE-306] on sensitive API handlers. The src/app/api/providers/* route handlers do not invoke a session, token, or middleware check before processing requests. Provider management is treated as a public capability rather than a privileged administrative function.

Attack Vector

The attack vector is network-based and requires no privileges or user interaction. An attacker sends standard HTTP requests to the /api/providers/* endpoints of a reachable 9Router instance. GET requests enumerate providers and leak credential material. POST and PUT requests inject or modify provider entries to redirect AI traffic. DELETE requests remove provider configurations and disable the service.

No verified public exploit code is available. Refer to the GitHub Security Advisory GHSA-vjc7-jrh9-9j86 and the VulnCheck Advisory on 9Router for technical details.

Detection Methods for CVE-2026-59801

Indicators of Compromise

Unauthenticated HTTP requests to paths matching /api/providers or /api/providers/* in web server or reverse proxy logs
Unexpected POST, PUT, or DELETE requests targeting provider endpoints from external IP addresses
Provider configuration entries pointing to unknown or newly registered domains
Sudden disappearance of previously configured AI providers or service outages in 9Router

Detection Strategies

Review application and access logs for requests to /api/providers/* that lack authenticated session cookies or bearer tokens
Diff current provider configurations against a known-good baseline to identify unauthorized additions or endpoint changes
Alert on 9Router audit or configuration changes originating from IP addresses outside the administrative network

Monitoring Recommendations

Forward 9Router access logs to a centralized logging or SIEM platform for retention and query
Monitor egress traffic from the 9Router host for connections to unexpected AI provider domains
Track HTTP response sizes for /api/providers GET requests, since credential enumeration returns larger payloads than normal health checks

How to Mitigate CVE-2026-59801

Immediate Actions Required

Restrict network access to the 9Router management interface using firewall rules, a VPN, or a reverse proxy with authentication
Rotate all API keys, OAuth tokens, and provider credentials configured in 9Router, since exposure must be assumed on any internet-reachable deployment
Audit existing provider configurations and remove any entries that point to unrecognized endpoints
Upgrade to a fixed release once the maintainer publishes a version above 0.4.41

Patch Information

Refer to the GitHub Security Advisory GHSA-vjc7-jrh9-9j86 for the authoritative patch status. At the time of publication, all versions through 0.4.41 are affected. Apply the vendor update as soon as it is released and re-verify that authentication middleware is enforced on /api/providers/* routes.

Workarounds

Place 9Router behind a reverse proxy such as Nginx or Caddy that enforces authentication on /api/providers/* paths before requests reach the application
Bind the 9Router service to 127.0.0.1 or an internal interface and require SSH port forwarding for administrative access
Apply network segmentation so only trusted administrative hosts can reach the 9Router HTTP port

bash

# Example Nginx configuration restricting provider API access
location /api/providers/ {
    allow 10.0.0.0/8;
    deny all;
    auth_basic "9Router Admin";
    auth_basic_user_file /etc/nginx/.htpasswd;
    proxy_pass http://127.0.0.1:3000;
}