An out-of-bounds read was addressed with improved input validation. This issue is fixed in macOS Big Sur 11.4, Security Update 2021-003 Catalina, Security Update 2021-004 Mojave, iOS 14.6 and iPadOS 14.6. Processing a maliciously crafted USD file may disclose memory contents.
https://support.apple.com/en-us/HT212531
https://support.apple.com/en-us/HT212530