Comment # 12 on bug 1187011 from Larry Finger

The usual interpretation of a kernel version such as X.Y is not as a decimal
number, but as major version X, and minor version Y. Thus 5.13 is 10 releases
after 5.3. Each such release takes a minimum of 9 weeks, thus 5.3 is pretty old
as things go in the software business.

If you insist on using the .run files from Oracle on your systems, then you
will need to get Oracle to make the changes that support Leap 15.3, or you will
need to fix the code yourself. If you choose the latter, then file
fixes_for_leap15.3.patch at site
https://build.opensuse.org/package/show/openSUSE%3AFactory/virtualbox will show
you what you need to do.

On the other hand, you can install the VirtualBox packages from the Leap 15.3
repos. Almost all users follow this route as they have the necessary patches to
allow them to build. That is my main duty as the maintainer of the software.