Security update for git on mac
For GitHub client for Mac, you have two options to get the latest version:


Download from GitHub.
Open GitHub app and go to Check for updates.


If you install the command line git through homebrew you have to type the following in your terminal:

brew update
brew upgrade


Apple command line git is on git version 1.9.3 (Apple Git-50) and there is no update available for the moment.

This is the official post from GitHub announcing the vulnerability.