[paoValle]

devServer.host: 'my-app.localhost' was announced as reachable from the network, and the Network: hint was suppressed for it: the check compared the requested hostname against an exact-match set, so any name under .localhost read as a public host. RFC 6761 §6.3 resolves localhost and every name under it to loopback.

The address the socket actually bound answers the question directly — a loopback bind means only this machine can connect, whatever the host was called — and it also covers a hosts-file entry that maps a name to loopback. The existing isLoopbackAddress helper is reused, so 127.0.0.0/8 and IPv4-mapped forms come with it.

packages/nuxt-cli/test/unit/listen.spec.ts: 61 passed, including two new cases on createListener (a .localhost name bound to loopback does not warn; a name bound to a LAN address does) and one on a real bind to 0.0.0.0. Against main the .localhost case fails with the warning present. eslint is clean on the three touched files; tsc --noEmit reports only the pre-existing @nuxt/cli workspace-resolution error, which needs pnpm -r build first.

Fixes #1644.

[github-actions]

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[codspeed]

Merging this PR will not alter performance

1 warning

⚠️ 2 benchmarks are dominated by system calls

System calls cannot be simulated consistently and are left out of the measure. The reported value understates the real cost. Switch to the Walltime instrument to measure them.

Learn more about system calls

See affected benchmarks

✅ 2 untouched benchmarks

---

_{Comparing paoValle:fix/localhost-loopback-warning (9882d57) with main (cd8f364)}

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
⚠️ Please upload report for BASE (main@cd8f364). Learn more about missing BASE report.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1649   +/-   ##
=======================================
  Coverage        ?   84.56%           
=======================================
  Files           ?      183           
  Lines           ?    11790           
  Branches        ?     3379           
=======================================
  Hits            ?     9970           
  Misses          ?     1533           
  Partials        ?      287           

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