Apple has issued three Mac security updates: Security Update 2016-001 El Capitan, Security Update 2016-005 Yosemite, and Safari 9.1.3 for OS X 10.9.5 Mavericks and OS X 10.10.5 Yosemite. All three updates are related to the major vulnerabilities discovered in iOS by Citizen Lab and Lookout, as we reported in “iOS 9.3.5 Blocks Remote Jailbreak” (25 August 2016). Due to the severity of these vulnerabilities, we encourage everyone to install these updates as soon as possible.
You can download the 414.9 MB Security Update 2016-001 and the 468 MB Security Update 2016-005 directly from Apple’s Web site, though it’s easier to install them via Software Update. Safari 9.1.3 is available only via Software Update.