[macOS] ChatGPT hangs at 100% CPU during Finder file drag

What version of the Codex App are you using?

ChatGPT 26.814.41407 (build 6720), powered by Codex and OWL.

What platform is your computer?

• macOS 26.6.2 (build 25G83)
• Apple Silicon, arm64
• Mac16,8 with Apple M4 Pro
• 24 GB memory

What issue are you seeing?

ChatGPT became completely unresponsive three times in one day, including twice within about 15 minutes. Activity Monitor showed the ChatGPT main process using one full CPU core. The window stopped responding, and Cmd-Q had no effect. Force termination was the only recovery.

The application worked normally again after each restart.

Two incidents coincided with native Finder drag sessions. In the first, a Finder drag activated ChatGPT before it stopped responding. WindowServer recorded another Finder drag immediately before the third freeze. The second incident followed a mouse interaction while ChatGPT was not the frontmost application.

What steps can reproduce the bug?

I do not yet have deterministic reproduction steps. The sequence immediately preceding two incidents was:

1. Open ChatGPT on macOS and use it normally.
2. Open Finder.
3. Drag a file or screenshot from Finder toward the ChatGPT window.
4. Move or drop the item over ChatGPT.
5. ChatGPT stops responding and the main process reaches approximately 100% CPU.

What is the expected behavior?

ChatGPT should accept or reject the file drop without becoming unresponsive. Cmd-Q should continue to quit the application.

Diagnostic evidence

| Incident | Evidence |
| --- | --- |
| 17:45 | macOS recorded a 150.84-second hang. ChatGPT had already been unresponsive for 146 seconds when sampling began. All 46 main-thread samples contained the same AppKit mouse-down and window-drag stack. |
| 21:18 | macOS recorded exactly 90 seconds of CPU time over 90 seconds, or 100% average CPU. ChatGPT used 313 MB and was not the frontmost application. All 14 samples contained the same AppKit stack. |
| 21:32 | WindowServer recorded a Finder drag window, then began clearing ChatGPT's event queue 244 ms after mouse-down. WindowServer received mouse-up, but ChatGPT remained unresponsive until force termination about 56 seconds later. |

The common main-thread stack in both macOS diagnostic reports is:

-[NSApplication(NSEventRouting) sendEvent:]
-[NSWindow(NSEventRouting) sendEvent:]
-[NSWindow(NSEventRouting) _handleMouseDownEvent:isDelayedEvent:]
-[NSWindow(NSWindowResizing) _hitTestWithHysteresisCheck:forEvent:allowWindowDragging:]
+[NSWindow(NSWindowResizing) _mouseHysteresisCheck:withExpiration:andDistance:finalMouseLocation:]

The first hang report recorded a 509 MB ChatGPT footprint, thermal pressure level 0, and 226.72 GB of free disk space. The second report recorded a 313 MB footprint.