An out-of-bounds write issue was addressed with improved input validation. This issue is fixed in Security Update 2022-004 Catalina, macOS Monterey 12.4, macOS Big Sur 11.6.6. Processing maliciously crafted web content may lead to arbitrary code execution.
https://support.apple.com/en-us/HT213256
https://support.apple.com/en-us/102770