https://arstechnica.com/gadgets/2022/02/apple-patches-security-holes-and-bugs-with-ios-15-3-1-and-macos-12-2-1/

Apple today released updates for iOS/iPadOS, macOS, and watchOS that primarily address bugs and security vulnerabilities.

iOS 15.3.1 is a minor update, feature-wise, for most users. It fixes a problem with Braille displays and addresses an arbitrary code execution vulnerability.