CVE 2021-30734
Multiple memory corruption issues were addressed with improved memory handling. This issue is fixed in tvOS 14.6, iOS 14.6 and iPadOS 14.6, Safari 14.1.1, macOS Big Sur 11.4, watchOS 7.5. Processing maliciously crafted web content may lead to arbitrary code execution.
See the 
CVE page on Mitre.org
for more details.
