For some strange reason Oracle Virtualbox 7 is still not available through the Mint Repos in early 2024. And for some even more strange reasons Oracle themselves offer their own Debian/Ubuntu/Mint online (apt) repository, but seem NOT to make sure that people are using this method, so that users will receive future updates to the packages automatically. Oracle provides all the information for that, but it's unnecessarily spread out and not provided in a compact form, IMHO.

So for convenience i assembled all the details into one simple howto manual.

This manual has been tested on Linux Mint 21 only. However it may work with other Distros as well, It's on you to test and adapt.

1. NOTE: This whole section is done by the root User! So open some terminal and enter sudo -i to become ROOT.
2. Based on the information from https://www.virtualbox.org/wiki/Linux_Downloads we need to prepare apt so it will trust the Oracle packages. Therefor we download their GPG Keys and install them:

   wget -O- https://www.virtualbox.org/download/oracle_vbox_2016.asc | sudo gpg --yes --output /usr/share/keyrings/oracle-virtualbox-2016.gpg --dearmor
   

3. Add Oracle's UBUNTU Jammy (matches Linux Mint 21) online repository to your APT configuration:

   echo "deb [arch=amd64 signed-by=/usr/share/keyrings/oracle-virtualbox-2016.gpg] https://download.virtualbox.org/virtualbox/debian jammy contrib" >/etc/apt/sources.list.d/oracle-virtualbox-jammy.list
   

4. Update your APT database and then install the available Virtualbox 7 packages:

   aptitude update
   aptitude search virtualbox
   aptitude install virtualbox-7.0
   

5. If you primary Linux user account wants to use real world USB devices within the Virtualbox environment (most likely!) you also need to make sure that this account has been added to the vboxusers group first. Else Virtualbox will complain about USB devices on every start:

   adduser <YourPrimaryVirtualboxUser> vboxusers
   

6. Done all that, close all Terminals and try to start the Virtualbox for the first time as a normal user. It should open (empty) but without any error messages.
7. Enjoy!

— Axel Werner 2024-01-06 10:44