On Monday afternoon, Apple issued a second test of the Rapid Security Response system found in iOS 16.4.
The company plans to use Rapid Security Response updates to quickly fix security flaws that hackers are actively exploiting. It's the second update for iOS 16.4 beta testers, as Apple released the first one just five days ago.
Users can find the update in Settings > General > Software update and look for iOS Security Response 16.4(b). Apple is likely still testing the update feature until it believes the system is perfect for official releases. It is possible to revert to the previous iOS version for users who trigger the Rapid Security Response update and have issues.
The company is currently testing the next versions of its operating systems, and all should arrive sometime in the next month.