Sprint is not only looking to push updates to the Nexus 5 and Nexus 6 with fixes for the Stagefright exploit, but also a number of other phones at the same time. According to updates on Sprint's software pages, the carrier will be pushing out fixes for a number of Samsung phones as well. Those phones include:

The updates are set to begin pushing out today, though it may be a day or two before you see it on your phone. If you want to check now for the update, head into your phones Settings, then System Update, and finally check for the update. If you have already received the update on one of these phones, or a different one, let us know in the comments below.

Source: Sprint (1),(2),(3),(4)