Multiple processes span with 100 %CPU usage in activity monitor

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 opened VS Code and left my computer for some time. The fan started going on and I checked Activity Monitor to see what could be causing a brand new M5 Macbook pro to overheat if I had literally nothing open except the VS Code app with no activity at all.

The activity monitor registered 4 Claude processes with 100% CPU use. I killed them all. I restarted VS Code and the Claude Code extension was irresponsive. I created a session in the teminal and it spawned 2 processes with 100 %CPU usage.

I restarted my computer, VS Code opened up and 2 claude 100 %CPU processes started, but claude remained unresponsive in VS Code. I closed VS Code, started a claude session in terminal and I currently have 4 claude PIDs all with 100 %CPU usage.

<img width="941" height="180" alt="Image" src="https://github.com/user-attachments/assets/7a971b0c-8952-4f82-9962-7723f96adb30" />

Claude version: 2.1.29 (Claude Code)
MacOS Tahoe Version 26.2
Apple M5 16 GB - 1TBSSD

What Should Happen?

Nothing should ever require 100 %CPU usage of a brand new M5 Macbook Pro

Error Messages/Logs

Steps to Reproduce

Just open the terminal and write claude or just open VS Code and activate the Claude Code extension

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.29 (Claude Code)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

VS Code integrated terminal

Additional Information

_No response_