[BUG] Claude Desktop Windows - SSH doesn't respect `StrictHostKeyChecking=no` in SSH config

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

When using the latest Claude Code Desktop version and have Claude Code inside Desktop connect over SSH to a remote host defined in your SSH config entry in ~/.ssh/config, that entry when defining StrictHostKeyChecking no and UserKnownHostsFile /dev/null or even UserKnownHostsFile NUL doesn't get respected and it throws a host key verification failure when SSH'ing in.

What Should Happen?

It should completely respect the SSH config per SSH spec.

Error Messages/Logs

host key checking failed in SSH failure modal in Claude Desktop

Steps to Reproduce

1. Open latest Claude Desktop
2. Try to SSH into a remote host defined in ~/.ssh/config in Windows C:\Users\<username>\.ssh\config where StrictHostKeyChecking no and UserKnownHostsFile /dev/null are defined.
3. SSH will fail due to host key checking failed.

To force it to work, we have to do ssh-keyscan -t ed25519 <host> and add it to known_hosts file in Windows to force Claude Desktop to work on Windows contrary to what's defined in the SSH config.

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

Claude Desktop: 1.21459.3 (e0f338)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Other

Additional Information

_No response_