Yes. The announcement about bintray going away said to download the addons kar file and place it in your addons folder. This link should work with 2.5.11. It just has some addons updated.
or to update to 2.5.12 or to 3.X.
It might work to reconfigure the mvn location.
For all details see the information about troubleshooting: openHAB 2.5.x and the sunset of Bintray
according to the original post / thread title I assume you mean you would like to update from 2.5.11 to 2.5.12.
You use openhabian ? First make sure that openhabian updates itself to the latest version.
Then in openhabian config menu you can update openhab.
As you use openhabian you have an apt installation of the packages which manually can be updated by doing “sudo apt-get update && sudo apt-get upgrade”
Be aware of that this will update all linux packages including OH2 to the latest OH2 package.