The Stagefright vulnerability was initially reported to Google in April 2015 and then publicly in July, just prior to the widely hyped talk at the Black Hat security conference in Las Vegas. Exodus Intelligence security researcher Jordan Gruskovnjak noticed that there seemed to be a severe problem with the proposed patch. Jordan crafted an updated firmware flashed to a Nexus 5 device to bypass the patch and was greeted with the following crash upon testing. As the code was not yet shipped to Android devices, we had no ability to verify this authoritatively.”]
Source: https://blog.exodusintel.com/2015/08/13/stagefright-mission-accomplished/