Details have been released for an unpatched vulnerability in MacOS 10.14.5 (Mojave) and below that allows a hacker to execute arbitrary code without user interaction. By leveraging the flaw it is possible to bypass Gatekeeper, the built-in defense in OS that guards the operating system against running untrusted applications. The attack is valid and was replicated by Sabina Alexandra ..tef..nescu, security professional and co-founder of Security Espresso, a community at the intersection of programming and security.
Source: https://www.bleepingcomputer.com/news/security/new-unpatched-macos-gatekeeper-bypass-published-online/