Apple is recommending Mac users update their systems after revealing that hackers exploited two vulnerabilities in its software. The company issued two bug fixes on Tuesday addressing issues in WebKit and JavaScriptCore,

In a security advisory on its website, Apple said it was aware of two vulnerabilities that “may have been actively exploited on Intel-based Mac systems.” The bugs are considered “zero day” vulnerabilities because they were unknown to Apple at the time they were exploited.

Apple has rolled out a software update to address security flaws that have been actively exploited by cybercriminals to target Intel-based Mac systems. In a recent security advisory, Apple confirmed awareness of two vulnerabilities that may have been exploited in attacks on Intel-powered Macs.