[Windows][Codex Desktop] In-app browser crashes Codex when opening localhost

What version of the Codex App are you using (From “About Codex” dialog)?

26.803.10989.0

What subscription do you have?

Business

What platform is your computer?

Microsoft Windows NT 10.0.26100.0 x64

What issue are you seeing?

Codex Desktop crashes when an agent initializes the in-app browser and navigates to a locally hosted Flask application.

The browser operation returns aborted, shortly after which the entire Codex Desktop app closes.

This has happened approximately six times across multiple tasks. Shell-only testing works normally, and avoiding the in-app browser prevents the crash.

What steps can reproduce the bug?

1. Start a Flask application on http://127.0.0.1:5000.
2. Ask Codex to inspect or test it using the in-app browser.
3. Codex initializes the browser and attempts to navigate to the local URL.
4. The browser operation returns aborted.
5. Codex Desktop crashes.

What is the expected behavior?

The local page should open in the in-app browser. If navigation fails, the error should be contained and Codex Desktop should remain running.

Additional information

The local Flask application remains available and works normally outside the Codex in-app browser.

Start by reproducing the crash on Windows with a Flask app at http://127.0.0.1:5000 and the Codex in-app browser. Trace the browser navigation that returns “aborted” and the resulting desktop shutdown. Done means the local page opens successfully or navigation errors are contained without closing Codex Desktop.