Fortunately after a moderate time i was able to check the situation and revert it, however, the same crash scenario happened again.
One kaya user was trying out robustness of the site and sent some large data, which seems to have caused one dependency library to crash, provoking a reaction on the core service.
That particular situation was repeated this morning to reproduce, and it is now adressed to not happen.
Web clients are particularly easy to fool around with and although we dont expect to get critical issues like this, we will promptly fix and address them. Thanks to this user a vulnerability is now known to us and we can not only fix it , but think in the future in terms of preventing it.
Kaya is now up and stable for use.