Advisories for Npm/@Acastellon/Auth package

2026

@acastellon/auth: Authentication bypass via spoofable headers in validateToken()

@acastellon/auth v2.2.0 appears to allow an unauthenticated authentication bypass in validateToken() through spoofable auth-user and Host request headers. The validateToken middleware contains a service-to-service bypass for auth-user: service-brother when req.get('host').startsWith(getHostName()). Both values involved in the check can be influenced by an unauthenticated HTTP client: auth-user is a request header, and Host is also client-controlled. As a result, a remote unauthenticated attacker can send a request with crafted headers and bypass …