Node "listen EACCES permission denied" on a Privileged Port in CI - Fix It

listen EACCES means the process tried to bind a port it is not allowed to use. Ports below 1024 are privileged and a non-root CI user cannot bind them.

What this error means

A server start in CI throws Error: listen EACCES: permission denied 0.0.0.0:80 (or another low port) because the unprivileged runner user may not bind privileged ports.

node

Error: listen EACCES: permission denied 0.0.0.0:80
    at Server.setupListenHandle [as _listen2] (node:net:1792:21)
    at listenInCluster (node:net:1865:12) {
  code: 'EACCES', port: 80
}

Common causes

Binding a port below 1024 as a non-root user

Privileged ports require elevated capability; the CI runner user lacks it, so the bind is denied.

A hardcoded production port in tests

Test config reuses the production port (80 or 443) instead of an unprivileged test port.

How to fix it

Use an unprivileged port

Bind to a port above 1024 (or 0 for ephemeral) in the CI environment.
Drive the port from an env var so production keeps its low port.

JavaScript

const port = Number(process.env.PORT) || 3000;
server.listen(port);

How to prevent it

Read the listen port from configuration, default tests to an unprivileged or ephemeral port, and never hardcode privileged ports into code that runs as a non-root CI user.