I had the same problem (running Fedora 38), and this post really helped me - it goes through the whole MOK generation/enrollment and then provides a script to automatically sign the modules. I had to make a couple of adjustments to make it work on my system and to automatically load the modules with modprobe , but now I just run /sbin/vboxconfig; /root/bin/sign-vbox-modules each time my kernel gets updated and can use VBox fine again.