SEP coverage for Macs / Is the new security flaw covered by SEP at all?

Does SEP only scan for Windows-related viruses on a Mac?

Today I found out about this.

http://www.engadget.com/2015/04/10/osx-security-flaw/

If we stick with Mavericks (because Yosemite has glitches), will SEP protect the Mac from this security flaw?

It's a choice between glitchy Yosemite and less-secure Mavericks from what I see.