Following the Z2 and Z3 models, older Sony Xperia Z units are set to get the Android 5.1.1 Lollipop update with build 10.7.A.0.222. However, the new build does not contain a security patch for the Stagefright vulnerability according to reports.

Sony first updated its devices to Android 5.1.1 Lollipop starting with Xperia Z2 and Z3 in July, with build 546. The Lollipop update made the system more stable, fixed up some issues, and added a few features. Lollipop first presented the heads-up notifications system and the 'Until next alarm' feature with its Priority and None modes. There was also LinkedIn and SmartWear integration for the Xperia units.

GSMArena enumerates the Sony Xperia models that are currently able to receive the 5.1.1 Lollipop update. These are the Xperia Z C6602 and C6603, Xperia ZL C6503 and C6506 Xperia ZL units, Xperia ZR C5503, and Xperia Tablet Z Wi-Fi SGP311 and SGP312, and the Xperia SGP321 Tablet Z with LTE and WiFi.

According to a report by International Business Times, the Stagefright vulnerability remains unfixed in the latest build for Android 5.1.1 Lollipop released by Sony. The company said in earlier reports that it would release a build version with a patch to fix the vulnerability.

The Xperia Z3 and Z2 units received the patches in the second build update 23.4.A.0.580. There are speculations that the Stagefright patch will arrive at the second build for older Xperia Z models.

Android Geeks gave instructions on how Sony Xperia users can get the Android 5.1.1 update for their devices. Once it is available for download, the OTA update shows up in the device's notifications. The user just needs to tap on it and follow the instructions displayed on the screen. An important thing to remember is that only devices that have an official Android build may receive OTA updates.

There are rumors going around that some Sony devices will not be able to receive Android 5.1.1 Lollipop updates but will directly get Android 6.0 Marshmallow. Yet, there is no official date of when Android 5.1.1 Lollipop will roll out to Sony Xperia devices.