A logic issue was addressed with improved validation. This issue is fixed in iOS 14.7, macOS Big Sur 11.5, Security Update 2021-004 Catalina, Security Update 2021-005 Mojave. Processing a maliciously crafted image may lead to a denial of service.
https://support.apple.com/en-us/HT212603
https://support.apple.com/en-us/HT212602