I don't think they have updated any of their devices to fix Stagefright. Also haven't see where they actually answer any of your questions about it either. Very disappointing to me.
Hi, they've updated the Galaxy Note 4, S5, S6 and S6 Edge. So yes, they're updating devices. So hopefully yours is around the corner!
CJMIA noted on 17 Aug that the Galaxy Note 4, S5, S6 and S6 Edge were updated. As of today, my Droid MAX is still vulnerable to CVE-2015-3829, 3864, 3827, 3824, and 1538.