CVE 2021-30799
Multiple memory corruption issues were addressed with improved memory handling. This issue is fixed in iOS 14.7, macOS Big Sur 11.5, Security Update 2021-004 Catalina, Security Update 2021-005 Mojave. Processing maliciously crafted web content may lead to arbitrary code execution.
See the 
CVE page on Mitre.org
for more details.
