Chrome native host crashes on Windows 11 after March 2026 security updates (Bun assertion failure)

Bug Description

The Chrome native host (--chrome-native-host) crashes immediately on startup with a Bun internal assertion failure. This breaks the Claude in Chrome browser extension integration entirely.

Environment

• Claude Code versions: v2.1.73 and v2.1.74 (both affected)
• OS: Windows 11 Pro 10.0.26200
• Bun version: v1.3.11 (bundled)
• CPU: x64 (baseline) with sse42, avx, avx2, avx512

Steps to Reproduce

echo "" | claude --chrome-native-host 2>&1

Crash Output

[Claude Chrome Native Host] Initializing...
[Claude Chrome Native Host] Creating socket listener: \.\pipe\claude-mcp-browser-bridge-Default
============================================================
Bun v1.3.11 (01210fb6) Windows x64 (baseline)
...
panic(main thread): Internal assertion failure
oh no: Bun has crashed. This indicates a bug in Bun, not your code.

Bun Crash Report

https://bun.report/1.3.11/e_101210fbEkgggC+/vlG+oxB6ptohB0smihB__6ojo3CA0eNrzzCtJLcpLzFFILC5OLSrJzM9TSEvMzCktSgUAiSkKPg

Additional Context

• The Chrome extension was working correctly prior to March 11, 2026
• Two Windows security updates were installed around the time it broke:
• KB5083532 (installed Mar 11, 2026) — Security Update
• KB5079473 (installed Mar 12, 2026) — Security Update
• The native messaging host manifest and registry entries are correctly configured
• The crash occurs on both v2.1.73 and v2.1.74, which both bundle the same Bun v1.3.11
• Crash happens immediately after attempting to create the named pipe socket listener
• Likely root cause: Windows security patches changed named pipe or stdin handling in a way that triggers a Bun assertion failure