[BUG] Claude Code crashes with 100%+ CPU usage on ARM (v2.1.27)

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?

I'm using Ubuntu Linux on ARM. Previously, the Claude Code CLI was using 50% CPU, but now it's using over 100%, and the OS kills the process. This happens even with a basic prompt like "hello" - it freezes with 100%+ CPU and then crashes. It was working fine in version 2.1.25, so I've downgraded to that version.

<img width="1168" height="404" alt="Image" src="https://github.com/user-attachments/assets/e157e3e8-b756-4c7a-a4a7-8a7d874d269e" />

What Should Happen?

Claude Code should not use so much CPU. The performance should be as good as 2.1.25.

Error Messages/Logs

Steps to Reproduce

1. launch claude
2. type "hello" in the message area.
3. top command shows 100% cpu usage, then after a minute or so the OS kills the process.

Claude Model

Not sure / Multiple models

Is this a regression?

Yes, this worked in a previous version

Last Working Version

2.1.25

Claude Code Version

2.1.25

Platform

Anthropic API

Operating System

Ubuntu/Debian Linux

Terminal/Shell

Non-interactive/CI environment

Additional Information

_No response_