An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in tvOS 15.5, watchOS 8.6, macOS Big Sur 11.6.6, macOS Monterey 12.3.1, iOS 15.4.1 and iPadOS 15.4.1. An application may be able to execute arbitrary code with kernel privileges. Apple is aware of a report that this issue may have been actively exploited..
https://www.tenable.com/cyber-exposure/tenable-2022-threat-landscape-report
https://support.apple.com/en-us/HT213256
https://support.apple.com/en-us/103000
https://support.apple.com/en-us/HT213254
https://support.apple.com/en-us/HT213253