Apple today released Safari version 15.6.1 for the older macOS Big Sur and macOS Catalina operating systems. The update includes an important security fix for a WebKit vulnerability that could lead to arbitrary code execution, according to Apple.

Apple said it is aware of a report that the WebKit vulnerability may have been actively exploited, so updating Safari is highly recommended.

Apple released macOS Monterey 12.5.1, iOS 15.6.1, and iPadOS 15.6.1 yesterday with fixes for both WebKit and kernel vulnerabilities. As noted by Mr. Macintosh on Twitter, a fix for the kernel-related vulnerability has yet to be released for macOS Big Sur or macOS Catalina, but it's unclear if that vulnerability affects those operating systems.