I also got the same segfault after upgrading to CentOS 6.5. The VirtualBox gui segfaults before it appears, and I can not start the VMs from the terminal either. Upgrading or downgrading to various VirtualBox or kernel versions did not work either. A workaround for me was to start the VMs using the terminal with only a simple GUI (sdl), not full GUI. The command is described in the documentation. https://www.virtualbox.org/manual/ch08.html#vboxmanage-startvm VBoxManage startvm "machine-name" --type sdl You lose the VB-menus, but all hotkeys still works. This workaround was tested with CentOS 6.5, kernel 2.6.32-431.3.1.el6.x86_64 and VirtualBox 4.2.22 from virtualbox.org-repo.