Internet-Security.com TCP port 19000 details

Expo CLI (React Native/Expo) runs its development server on TCP 19000 by default; the Expo Go app connects to this port to fetch the app manifest and JavaScript bundle (with companion ports 19001 for logs/WS and 19002 for DevTools).
In practice, when you run “expo start,” Node.js listens on 19000 and mobile devices on the same network load the app through http://:19000.
Envoy Proxy commonly binds its admin interface to TCP 19000 in many official examples and real deployments, where admins curl http://:19000/ for stats, config dumps, and control actions.
Security note: Exposed Expo/Metro dev servers and Envoy admin endpoints on 19000 have been abused by attackers; they can retrieve source bundles/sourcemaps (potentially leaking secrets) or issue admin actions (e.g., /quitquitquit) if left open to the internet.

TCP 19000