Security Update 2016-001 (Mavericks and Yosemite)
Apple has issued Security Update 2016-001 for OS X 10.9 Mavericks and 10.10 Yosemite with a single patch that affects the older California-themed OS releases. (The rest of the listed security fixes apply only to the concurrently released OS X 10.11.3 El Capitan; see “OS X 10.11.3 and iOS 9.2.1 Bring Bug Fixes,” 19 January 2016.) The update improves memory handling with libxslt (the library used to perform XSL transformations on XML documents) to avoid a type confusion that could allow a maliciously crafted to execute arbitrary code. The security updates are available via Software Update or via direct download from Apple’s Support
Downloads Web site. (Free. For 10.9.5 Mavericks, 288.3 MB; for 10.10.5 Yosemite, 369 MB)
369 MB to fix a bug in one library? Sheesh…
Immediately after installing the Security Update our Mac Mail failed to perform and url load time greatly increased and some sites failed to load completely. Apple Care acknowledged 'some' issues with Mac Mail and slower Internet load speeds across all browsers. And the Security Update fix will be ready 'by when'?
I have the same issue. Trying to create new Internet Accounts does not fix the problem. My VPN does not work either anymore.
Be aware this could break your nvidia drivers for unflashed graphics cards on 10.10.5. After spending 5 days trying to get my system working the way I want between 2 computers and 3 OS they release this "wonderful" security update and I'm back where I started.
New Drivers here:
http://www.nvidia.com/download/driverResults.aspx/97606/en-us
After installing the update on OS X 10.9.5, I find that Mail crashes anytime their is an OpenVPN (Tunnelblick) connection established. VirtualBox has a similar problem.