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Codex Issues / #38175

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

Open 💬 2 comments Opened Aug 12, 2026 by SolusKossi
💡 Likely answer: A maintainer (github-actions[bot], contributor) responded on this thread — see the highlighted reply below.

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.

View original on GitHub ↗

2 Comments

github-actions[bot] contributor · 15 days ago

Potential duplicates detected. Please review them and close your issue if it is a duplicate.

  • #37968
  • #38098

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kcwl-gona · 11 days ago

Confirming that this still reproduces on a newer Windows Codex Desktop build.

Environment:

  • Codex Desktop: 26.810.7004.0 (x64)
  • Windows: 10.0.26200, x64
  • Date observed: 2026-08-17

Reproduction:

  1. Start or keep a local web service available on 127.0.0.1.
  2. Ask Codex to use the in-app Browser for UI verification.
  3. As soon as Browser Use is invoked / the embedded browser is opened, the Codex desktop app exits or crashes.
  4. Reopening Codex and avoiding Browser Use prevents the crash.

The behavior is reported as deterministic on this build: any Browser invocation triggers the crash. Shell/API-based checks continue to work.

During one Browser screenshot attempt, the tool stream also logged a Statsig POST timeout to ab.chatgpt.com (10 seconds). The screenshot itself was returned, so this may only be adjacent telemetry rather than the crash cause.

Expected:

  • Browser failures should be contained to the browser session/tab.
  • Codex Desktop should remain running, and the active task should continue.

No project credentials, browser contents, or business data are included in this report.