Cifs share mount on a VPS without cifs module build in kernel

Not sure, how much Kernel support it actually needs and if that support is available to you, but the GNOME Virtual file system (GVfs) could be an option. Try something like:

gio mount 'smb://username@host/sharedfolder' 

The mounted folder should show up within /run/user/$uid/gvfs. On older systems the executable might be gvfs-mount or gnome-mount.

Since GVfs uses the FUSE interface in order to run the file system driver in user space, there is a real possibility that it doesn't need Kernel support for the CIFS file system. However, it might rely on some other Kernel features necessary for the FUSE system. Let's hope your Kernel has it.

And, of course, it needs Gnome, or at least the GLib component - which is installed by default in most Desktop Unixes, but not necessarily on a server. So you may have to install GLib from the package manager of your distribution.

Also, be aware that the mounts that are created using FUSE drivers are only available to the user that mounted it. So this solution, even if it works, might not be good enough for your use case in a server, but that really depends on your exact use case.