Apple has just released OS X 10.10.5, the fifth (and likely last) major update to OS X Yosemite. It can be downloaded now through the Update tab in the Mac App Store, or you can look for standalone installers to hit Apple’s download page later in the day.

The update contains a fix for a bug that gives attackers unfettered root privileges, a feat that makes it easier to surreptitiously infect Macs with rootkits and other types of persistent malware. Shortly after the vulnerability was publicly disclosed, adware distributors started exploiting it in the wild so they could install potentially unwanted applications without requiring end users to enter system passwords.

The list of specific feature fixes is short: it improves Mail’s “compatibility with certain e-mail servers,” fixes a problem with GoPro camera imports into the Photos app, and a problem that kept Windows Media files from playing in QuickTime. The update also fixes an extensive list of security problems in Apache, Bluetooth, CloudKit, the OS kernel, and a handful of other apps and services—all of that information is available here.