Apple has confirmed to 9to5Mac that a software update will fix the iPhone 18 Pro bug that freezes and reboots the phone after a failed Face ID attempt. It should be out early next week. Apple is also reportedly testing iOS 27.0.1, which is likely the update with the fix. Apple hasn't published release notes for it yet.
If Face ID misses while it's guarding a locked app, an affected phone stops responding to touch and hard reboots a few seconds later. You can find a panic log in the iPhone Analytics section of Settings. It didn't hit every phone, but reader reports suggest it was fairly widespread. Some owners swapped their phone at Apple, thinking it was a hardware fault. That isn't necessary now. Apple also released watchOS 27.0.1 this week to fix random restarts on the Apple Watch Series 12 and Ultra 4.