The Google Project Zero team is well known for identifying errors and security flaws in systems like Google itself and other large companies. Most recently, they reported a “high severity” error found by them in the macOS kernel. It can provide an attacker with access to a computer without the knowledge of the user.
Security researchers have found that if changes are made to a custom image of a mounted file system, the virtual management system is not notified of them. Thus, it can potentially be accessed to perform actions in this system, while the owner of the computer does not know about it until it is already too late.
Apparently, Google first discovered this flaw in macOS back in November 2018. The company's specialists call the problem a serious one.
Fortunately, Apple recognized the error and began working on fixing it with Project Zero. The company intends to correct this deficiency in the future release of macOS, but the timing is still unknown.