A logic issue was addressed with improved state management. This issue is fixed in tvOS 14.6, iOS 14.6 and iPadOS 14.6, Security Update 2021-003 Catalina, macOS Big Sur 11.4, watchOS 7.5. Processing a maliciously crafted message may lead to a denial of service.
https://support.apple.com/en-us/HT212533
https://support.apple.com/en-us/HT212532
https://support.apple.com/en-us/HT212530