[BUG] [Windows] Bash tool causes BSOD (SYSTEM_SERVICE_EXCEPTION) on Windows 11 with HVCI enabled

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 Claude Code's Bash tool spawns a child process (e.g., Git Bash + gh.exe), the system
crashes with a BSOD (SYSTEM_SERVICE_EXCEPTION, BugCheck 0x3B) and automatically restarts.
Running the exact same command manually in PowerShell or Command Prompt works fine.

What Should Happen?

The command executes successfully (as it does when run manually in PowerShell)

Error Messages/Logs

0x0000003b (0x00000000c0000005, 0xfffff806dd555fd6, 0xffffc901264ad8f0, 0x0000000000000000)
0x0000003b (0x00000000c0000005, 0xfffff804a6155734, 0xffffb681f0aad8f0, 0x0000000000000000)
0x0000003b (0x00000000c0000005, 0xfffff800b2d53104, 0xffff828122b498f0, 0x0000000000000000)
(Note: offset 0x155734 repeats across reboots — same module, different KASLR base)

Steps to Reproduce

1. Enable HVCI/VBS in Windows 11 (Settings > Privacy & Security > Windows Security >

Device Security > Core isolation > Memory integrity: ON)

1. Open VS Code with the Claude Code extension
2. Ask Claude to perform a task that triggers the Bash tool (e.g., "Set up GitHub

authentication and list .claude directory")

1. Claude runs: gh auth status 2>&1 && echo "---" && ls "C:/Users/<user>/.claude/" 2>&1
2. System crashes and restarts with BSOD

Claude Model

Not sure / Multiple models

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

Claude Code: VS Code extension v2.1.145 (win32-x64)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Windows Terminal

Additional Information

BSOD: SYSTEM_SERVICE_EXCEPTION (0x3B), exception code 0xc0000005 (access violation)
BugcheckInfoFromEFI: true — crash too fast to write full dump via normal path
Minidump saved to C:\Windows\Minidump\

Using PowerShell tool instead of Bash tool avoids the crash entirely.