This issue was addressed with improved iframe sandbox enforcement. This issue is fixed in macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave. Maliciously crafted web content may violate iframe sandboxing policy.
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2021-1765.json"