A path handling issue was addressed with improved validation. This issue is fixed in macOS Big Sur 11.0.1, iOS 14.2 and iPadOS 14.2, tvOS 14.2, watchOS 7.1. A local attacker may be able to elevate their privileges.
https://support.apple.com/kb/HT212011
https://support.apple.com/en-us/HT211931
https://support.apple.com/en-us/HT211930
https://support.apple.com/en-us/HT211929
https://support.apple.com/en-us/HT211928