kernel upgrade

There is info about new kernel upgrade in https://forums.opensuse.org/forumdisplay.php/666-Security-Announcements

but

zypper ref && zypper up

does not offer it. Is please any additional action needed to get this upgrade ?

As I read it:

Description: The SUSE Linux Enterprise 15 SP2 kernel RT was updated to receive various security and bugfixes. The following security bugs were fixed:

the update you mention refers to the “RT” kernel, so if your install is a standard one you only have the “-default” kernel installed and the “nothing to do” seems appropriate.

The SUSE Linux Enterprise 15 SP2 kernel RT

openSUSE is not SUSE…

The kernel is inherited, quoting again from the announcement:

Package List: - openSUSE Leap 15.2 (x86_64):

kernel-rt-5.3.18-lp152.3.8.1

well thank you