An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in iOS 15.6.1 and iPadOS 15.6.1, macOS Monterey 12.5.1. 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/HT213486
https://support.apple.com/en-us/HT213443
https://support.apple.com/en-us/103006
https://support.apple.com/en-us/103005
https://support.apple.com/kb/HT213486
https://support.apple.com/kb/HT213443
https://support.apple.com/en-us/HT213413
https://support.apple.com/en-us/HT213412
http://seclists.org/fulldisclosure/2022/Oct/49