A memory corruption issue was addressed with improved state management. This issue is fixed in macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave, watchOS 7.3, tvOS 14.4, iOS 14.4 and iPadOS 14.4. A malicious application could execute arbitrary code leading to compromise of user information.
https://support.apple.com/en-us/HT212149
https://support.apple.com/en-us/HT212148