Last night I received notification of a system update taking the HTC One M9 stock software to version 2.11.651.19 (at least on the Sprint varients), which addresses the Stagefright vulnerability as well as claiming device stability improvements and unspecified new and enhanced features.
The update clocks in at 54MB, and supposedly doesn’t work if you’re rooted due to checking to see if the system partition has been modified (it definitely doesn’t work if you’re not running stock recovery).
If you are running stock rooted, it appears there’s a stock rooted image that you may be able to dirty flash over your system, although if you’re not S-OFF you may have issues running with the wrong radio firmware. We’ll have to see on that one as it’s fairly early in the release and nobody has so far bricked a device or cursed anyone’s name.
Doesn’t appear that the stock rooted image above has the new aboot, hboot, adsp, and radios. These were signed/updated on the 25th of last month, I’m assuming they’re all new, although whether they’re good and stable, who knows.
If you find any of the mysterious stability improvements or new and enhanced features, drop us a line. I’m struggling to find any documentation of why you should update other than the Stagefright fix.