Earlier today, Sony filed for certification on a new update it’s planning to roll out for the Xperia M4 Aqua and Aqua Dual. Unfortunately, judging by the details included in the documentation, it doesn’t look like a big update, but we should see a full fix for the Stagefright vulnerability.
Many Xperia M4 Aqua users have been reporting that their handsets have been getting extremely hot during extended use, so Sony most probably have included a patch to control the heat of the processor in order to keep the device running at a safe temperature in this upgrade, too.
The update carries build number 26.1.A.2.147 for the single-SIM model as opposed to 26.1.B.2.129 for the dual-SIM variant, and will be available for all carrier bands in the United States in the not-too-distant future.
Via: Xperia Blog