unpushing this updates made package be removed from updates-testing , branched is now with qt5-5.11  and not with qt5-5.12 as you expect I think
Big regression ext4 file system corruption -> https://bugzilla.kernel.org/show_bug.cgi?id=201685 https://email@example.com/thread/JQYO43XQQEFBMLSQBSS46V3J3LVJ66FM/
This just hit Slashdot: "According to a text file uploaded on GitHub, Saint Petersburg-based researcher Sergey Zelenyuk has found a chain of bugs that can allow malicious code to escape the VirtualBox virtual machine (the guest OS) and execute on the underlying (host) operating system."
His github repo has the technical details. He shows how you can create a console shell to start on the host by using a buffer overrun in the guest: https://github.com/MorteNoir1/virtualbox_e1000_0day
The "disgruntled security researcher" part is difficult to read and understand due to broken English. More info is available on his github page.