A pair of new security vulnerabilities has been discovered in the framework used by a wide variety of Mac apps leaves them open to Man-in-the-Middle (MitM) attacks. The vulnerabilities affect Apple Mac apps that use an outdated and vulnerable version of the Sparkle updater framework. The Sparkle vulnerabilities affect both Mac OS X Yosemite and the most recent version of OS X El Capitan. Although the actual number of affected apps is not known, Radek estimated the number could be “huge”
Source: https://thehackernews.com/2016/02/apple-security-vulnerability.html