A memory corruption issue was addressed with improved validation. This issue is fixed in iOS 13.5 and iPadOS 13.5, tvOS 13.4.5, watchOS 6.2.5, Safari 13.1.1, iTunes 12.10.7 for Windows, iCloud for Windows 11.2, iCloud for Windows 7.19. Processing maliciously crafted web content may lead to arbitrary code execution.
https://support.apple.com/HT211168
https://support.apple.com/HT211171
https://support.apple.com/HT211175
https://support.apple.com/HT211177
https://support.apple.com/HT211178