The Kubuntu developers have announced the availability of the latest KDE Plasma 5.6.5 desktop environment, along with KDE Framework 5.23.0 in the Backports PPA repositories for Kubuntu 16.04 LTS users. Plasma 5.6.5 brings various bugfixes and new 5.23 framework introduces new fixes in KWallet, KWayland, Breeze and many more.
According to sources KDE Plasma 5.6.5 is the last maintenance release for the KDE Plasma 5.6 desktop environment series. Good news is if you're using Kubuntu 16.04 LTS, you can now upgrade to the KDE Plasma 5.6.5 desktop environment.
To update to latest KDE Plasma 5.6.5 just open up terminal in your Kubuntu and add the following Repository:
After adding the following repository,make an update command run and then wait for all the KDE Plasma 5.6.5 and KDE Frameworks 5.23.0 packages to be downloaded and installed. When the install operation finishes, please reboot your computer. That's it! You now have the latest KDE Plasma 5.6.5 in your Kubuntu 16.04 LTS.