A use after free issue was addressed with improved memory management. This issue is fixed in iOS 15.3 and iPadOS 15.3, watchOS 8.4, tvOS 15.3, Safari 15.3, macOS Monterey 12.2. Processing maliciously crafted web content may lead to arbitrary code execution.
https://support.apple.com/en-us/103177
https://support.apple.com/en-us/103176
https://support.apple.com/en-us/103175
https://support.apple.com/en-us/103172
https://support.apple.com/en-us/102848
https://support.apple.com/en-us/HT213059
https://support.apple.com/en-us/HT213058
https://support.apple.com/en-us/HT213057
https://support.apple.com/en-us/HT213054