I am logging here what I needed to do after I received an Kernel has changed message on my Virtualbox 7.0. After an Ubuntu 22.04 update. The message said I need to run "/sbin/vboxconfig" to rebuild Virtualbox for the new kernel.
On running "/sbin/vboxconfig" I received an error. In the log there was a message "warning: the compiler differs from the one used to build the kernel".
I needed to install gcc-12 after that the "/sbin/vboxconfig" command worked.
apt install gcc-12
Hope this helps