GHSA-8gmq-j984-vp4r: 9router: Unauthenticated LLM proxy access via /codex rewrite authorization bypass

Summary

9router exposes an OpenAI/Anthropic-compatible LLM proxy that is meant to require an API key through Next.js middleware. The middleware checks the original request path before a rewrite maps `/codex/*` to `/api/v1/responses`, and `/codex` is missing from the protected prefix list, so requests to `/codex/*` skip the key check. Tested on v0.4.80 (commit 23da7b1fe3bb8edd2bdbdb63fbbb15a476b02c56, Next.js 16.2.9), an unauthenticated remote request to `/codex/x` returned 200 OK where `/api/v1/responses` returned 401, letting attackers trigger upstream provider calls with operator-stored credentials.

Mitigation

The source does not state a fix yet. Check the original advisory for updates.

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