Join us in the #kubuntu chat room for support or the #kubuntu-devel chat room for development
Kubuntu uses the Launchpad bug tracker to keep track of problems found with the operating system and desktop environment. Users should file all bugs that they find in Kubuntu in the bug tracker. It is used to keep track of outstanding issues, issues that are being worked on, and fixes.
See here for more information on how to file bugs in KDE, Kubuntu's desktop and applications.
Helping with Bugs
A lot of bugs come in and help is needed to sort through them all, ensure they have all the needed information, confirm them, and decide on an importance. This process is called triaging. See information on how to help out and see here for related information specific to KDE.