Sure, as many other software with vulnerability, but with local software like brew (I wrote also [dotsoftware](http://g14n.info/dotsoftware) for the same reasons) you don't have it in your PATH so you are not using it.
Using local software has many benefits, among others, a shorter release cycle.
As I said, one config mistake or running a script which uses /usr/bin/git and you're subject to RCE. For example, many GUI programs, such as Atom editor, when not launched from terminal, don't know your PATH.
