VitestUI server not reachable from WSL

[mlarabi]

Describe the bug

When trying to run VitestUI server from a repo in WSL, although there is no errors in the terminal the server is not reachable when accessing the link.

> vitest --ui


 DEV  v3.1.4 /home/mlarabi/git/calx/markdown-mailer
      UI started at http://localhost:51204/__vitest__/

 ✓ tests/sun.test.js (1 test) 1ms
   ✓ adds 1 + 2 to equal 3 1ms

 Test Files  1 passed (1)
      Tests  1 passed (1)
   Start at  08:42:27
   Duration  269ms (transform 17ms, setup 0ms, collect 13ms, tests 1ms, environment 0ms, prepare 52ms)

 PASS  Waiting for file changes...
       press h to show help, press q to quit

It works if the repo is in Windows, but from WSL it doesnt. And the additional issue is that if I try to run VitestUI from WSL and then go back to Windows I am not able to start it there either as I get the following error:

> vitest --ui


⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯ Startup Error ⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯
Error: listen EACCES: permission denied ::1:51204
    at Server.setupListenHandle [as _listen2] (node:net:1917:21)
    at listenInCluster (node:net:1996:12)
    at GetAddrInfoReqWrap.callback (node:net:2205:7)
    at GetAddrInfoReqWrap.onlookupall [as oncomplete] (node:dns:134:8) {
  code: 'EACCES',
  errno: -4092,
  syscall: 'listen',
  address: '::1',
  port: 51204
}



 ELIFECYCLE  Command failed with exit code 1.

Which I assume that the server is still running after WSL attempt.

Reproduction

I tried using this minimal setup:

https://stackblitz.com/~/github.com/mlarabi/vitest-ui-not-working

If I run this on Windows it works. If I run this on WSL it works (no errors) but the server is not reachable from the browser. If I run this again on Windows after the WSL issue it doesnt work anymore.

System Info

Windows:

  System:
    OS: Windows 11 10.0.26100
    CPU: (20) x64 12th Gen Intel(R) Core(TM) i9-12900HK
    Memory: 12.38 GB / 31.68 GB
  Binaries:
    Node: 24.0.2 - C:\nvm4w\nodejs\node.EXE
    npm: 11.3.0 - C:\nvm4w\nodejs\npm.CMD
    pnpm: 10.11.0 - C:\ProgramData\chocolatey\bin\pnpm.EXE
  Browsers:
    Edge: Chromium (135.0.3179.66)
    Internet Explorer: 11.0.26100.1882
  npmPackages:
    @vitest/ui: ^3.1.4 => 3.1.4 
    vitest: ^3.1.4 => 3.1.4 

WSL:

  System:
    OS: Linux 6.6 Ubuntu 24.04.1 LTS 24.04.1 LTS (Noble Numbat)
    CPU: (20) x64 12th Gen Intel(R) Core(TM) i9-12900HK
    Memory: 12.65 GB / 15.46 GB
    Container: Yes
    Shell: 5.2.21 - /bin/bash
  Binaries:
    Node: 24.0.2 - ~/.nvm/versions/node/v24.0.2/bin/node
    npm: 11.3.0 - ~/.nvm/versions/node/v24.0.2/bin/npm
    pnpm: 10.11.0 - ~/.local/share/pnpm/pnpm
  npmPackages:
    @vitest/ui: ^3.1.4 => 3.1.4 
    vitest: ^3.1.4 => 3.1.4

Used Package Manager

pnpm

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• [x] The provided reproduction is a minimal reproducible example of the bug.