Apple released iOS Security Response 16.4 (a) today, just saying “This Rapid Security Response provides important security fixes and is recommended for all users.
The update shows under Settings > General > Software Update for those running the iOS 16.4 beta and isn’t labeled as a test.
However, when we saw Apple release a similar update during the iOS 16.2 beta, it wasn’t until after the fact that we learned it was indeed just a test.
But hypothetically, if an important flaw was discovered in the beta that couldn’t wait until the next release, this is the mechanism Apple would use to deliver a patch.
The security update comes in at just 20.9 MB in size.
