Unless you have a Nexus devices, who knows when you will get the patch, so you need to be proactive. Turn off MMS auto retrieval in your settings. If you are using Messenger (and you should, it's great), go into SETTINGS>ADVANCED and toggle auto-retrieve off.
The good news is that OEMs and carriers seem to be taking this seriously and are already starting to push out the patch. Still, it's going to take some time.