A new firmware with build number 23.4.A.1.236 has been certified for the Sony Xperia Z3, Xperia Z3 Compact and Xperia Z3 Tablet Compact. The new version compares to the current firmware release 23.4.A.1.232 and we imagine that Sony is fully patching the Stagefright exploit. The last update patched most of the exploits, but one new exploit emerged (CVE-2015-6602). We’ll keep you posted once the new firmware starts to roll.
Update: Looks like the same firmware has also been certified for the Xperia Z2 series.
Thanks leso60!