Apple released it's first Rapid Security Response (RSR) this week which is continuing to reach users. Rapid Security Responses are a new type of software release for iPhone, iPad, and Mac to deliver important security improvements between software updates. Further information can be found on Apple's Support Page
RSR updates are delivered only for the latest version of iOS, iPadOS and macOS — beginning with iOS 16.4.1, iPadOS 16.4.1, and macOS 13.3.1.