T-mobile S5 & Stagefright -- how concerned should I be?

A

AC Question

I just upgraded from an S3 to a brand new S5 (SM-G900T3, T-mobile) about 2 weeks ago. It's running lollipop 5.1.1, build LMY47X.G900T3UVU1FOF6.

I can't find anything online about a t-mobile stagefright update for the S5, and as far as "Walter" at t-mob tech support can tell, there's no information about an S5 update anywhere on the horizon. (Of course it took him a while to figure out what I was talking about, so I'm not too hopeful I was getting correct information...) I did see a ZDNET post that indicated that some of the vulnerabilities aren't usable by lollipop.

However, Lookout's Stagefright detector says I'm vulnerable...

So I've had MMS download turned off on for a week now, but my family sends group texts and photos by text on a regular basis, and it's a pain to have to download them manually.

Can someone tell me how concerned I need to be, and what I need to do to be reasonably safe?

I have to say I'm a little chapped that t-mobile has taken care of the S6/Edge and Note 5, but doesn't seem to be doing anything about the S5...

thanks!