https://arstechnica.com/gadgets/2021/04/actively-exploited-mac-0-day-neutered-core-os-security-defenses/

When Apple released the latest version 11.3 for macOS on Monday, it didn't just introduce support for new features and optimizations. More importantly, the company fixed a zero-day vulnerability that hackers were actively exploiting to install malware without triggering core Mac security mechanisms, some that were in place for more than a decade.