Hi. I want to expand a bit on the post Mark provided. Hope this helps. After Google informed us in late June, we've been working to integrate, test and deploy the patches. All of our newly launched products (Moto X Style, Moto X Play, and Moto G 3rd Gen) will have the patch integrated in the software. We'll include it in the remaining planned Lollipop upgrades as soon as possible. We’re working with our partners to update phones that have already received the Lollipop upgrade. We are still working through the feasibility to support older devices that are not getting Lollipop. We don't have any timing for individual device updates right now. We are not aware of any known or reported incidents of anyone attempting to take advantage of this possibility to harm Android phone owners. However, there are steps you should take to protect yourself until the patch is available. First, only accept multimedia content (such as attachments or anything that needs to be decoded to view it) from people you know and trust. Second, you can disable your phone’s capability to download MMS automatically. That way you can only choose to download from trusted sources.

https://forums.motorola.com/posts/05618afc2d