A type confusion issue was addressed with improved state handling. This issue is fixed in macOS Big Sur 11.0.1, watchOS 7.1, iOS 12.4.9, watchOS 6.2.9, Security Update 2020-006 High Sierra, Security Update 2020-006 Mojave, iOS 14.2 and iPadOS 14.2, watchOS 5.3.9, macOS Catalina 10.15.7 Supplemental Update, macOS Catalina 10.15.7 Update. A malicious application may be able to execute arbitrary code with kernel privileges.
http://seclists.org/fulldisclosure/2020/Dec/32
http://packetstormsecurity.com/files/161295/XNU-Kernel-Turnstiles-Type-Confusion.html