critical10.0
CVE-2026-46339
9router: Unauthenticated Remote Code Execution via unprotected MCP custom plugin routes
Impact
9Router is an AI router & token saver. From 0.4.30 until 0.4.37, 9Router's src/proxy.js middleware did not protect /api/cli-tools/* and /api/mcp/*, allowing unauthenticated registration of customPlugins through src/app/api/cli-tools/cowork-settings/route.js and command execution through the MCP bridge. This vulnerability is fixed in 0.4.37.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| npm | 9router | >= 0.4.30, < 0.4.37 | 0.4.37 |