Q: Does the OS X Mavericks reach its end of life?
Should I update to Yosemite?
"OS X 10.9.x and older remain vulnerable, since Apple decided not to patch these versions."
https://truesecdev.wordpress.com/2015/04/09/hidden-backdoor-api-to-root-privileg es-in-apple-os-x/
OS X Mavericks (10.9.5)
Posted on Apr 20, 2015 1:12 PM
Since Apple decided to make Mavericks and Yosemite free upgrades, they also decided to make the upgrade permanent. You cannot downgrade to Mavericks because it is no longer available. This is exactly the same practice as how Apple handles iOS upgrades.
However, Apple does not immediately abandon a just previous edition. Usually they continue support for up to seven years after which support is terminated. But with OS X the only updates that may appear in the future will be security updates. So, as of today 10.9.5 will only receive essential security updates. There won't be a 10.9.6.
Posted on Apr 20, 2015 1:19 PM