[BUG] Claude for Chrome: Authorize button causes infinite loop — X-Frame-Options: sameorigin blocks OAuth

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?

After clicking "Authorize" on the OAuth page (https://claude.ai/oauth/authorize?client_id=...), the page shows a spinner and then returns to the same authorization screen. Infinite loop, no side panel opens.

What Should Happen?

Side panel should open and tab group should be created after clicking Authorize.

Error Messages/Logs

Refused to display 'https://a.claude.ai/' in a frame because it set 'X-Frame-Options' to 'sameorigin'.

Failed to load resource: the server responded with a status of 403 ()
Failed to load resource: the server responded with a status of 405 ()
Unsafe attempt to load URL https://a.claude.ai/isolated-segment.html from frame with URL chrome-error://chromewebdata/. Domains, protocols and ports must match.

Steps to Reproduce

Install Claude for Chrome from Chrome Web Store
Click extension icon → follow OAuth login flow
Arrive at claude.ai/oauth/authorize page
Click "Authorize"
Spinner appears → page reloads back to same screen

Environment:

Chrome: 148.0.7778.216 (official build, 64-bit)
OS: Windows
Extension version: latest from Chrome Web Store
Account: claude.ai (not third-party provider)

Related issues: #17790, #34176

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

Claude 1.10628.2 (deee0a) 2026-06-03T20:08:36.000Z

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

_No response_