[BUG] Safari browser fails at login into Claude account via Google SSO

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 don't know if this is a bug with Safari or with Claude Code, but I figure it's more likely a bug with Claude because of how well-maintained the Safari browser is and because Claude is relatively new.

Here's the issue: I run /login in Claude Code, I select login with a Claude account with a subscription, and it takes me to my default browser, Safari, to open the Claude login page. It opens correctly and I login, but, after completing my Google SSO, it takes me to Claude and, after a bit of loading, it takes me back to the login page I started at with this message from Safari: "This webpage was reloaded because a problem occurred".

Also, I'm on MacOS Tahoe 26.5. This problem was still happening a few weeks ago when I was on a pre-20 version of MacOS.

Retrying with Chrome as my browser, it works perfectly fine.

This is a complicated issue with a bunch of possible culprits, so I'm not sure what's at fault here, but I thought it better to report it than to not.

What Should Happen?

The Claude login webpage on Safari should authenticate me and let me continue to the Claude Code app.

Error Messages/Logs

This webpage was reloaded because a problem occurred.

Steps to Reproduce

1. Pre-reqs: MacOS, Safari as default browser
2. open Claude Code (claude)
3. run /login
4. Select Claude account with a subscription as your login method
5. Sign in through Google SSO through the opened page on Safari.

Claude Model

None

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

2.1.149 (Claude Code)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

This issue is also present in other workflows which require Claude Authentication via web browser for Claude Code--in specific, the webpage repeatedly has an issue (in the same way as above) for joining a team on Claude.