We always ship Zorin OS with the latest version of Ubuntu's HWE kernel (currently 6.2), which is actively supported and tested for stability upstream.
Because Zorin OS 17 is based on an LTS version of Ubuntu (22.04.3), this kernel continues to receive updates and security patches from Canonical even if it's currently listed as EOL on the kernel.org site. For example, it received a few patches for some CVEs just over a week ago (see here).
You can keep track of the security updates and patches provided by Ubuntu (for the kernel and other patches) on the Ubuntu Security Notices website.
As before, the HWE kernel will continue to get rebased on newer Linux kernel versions every few months. That means Zorin OS users will automatically get access to these kernel upgrades through the normal software updates and point releases (like Zorin OS 16.3 and the upcoming 17.1).
For reference, we're expecting to release Zorin OS 17.1 in the February/March timeframe, which will come with the upgraded kernel 6.5.
The HWE kernel series will continue to receive updates and security patches for the life of the OS, until at least June 2027.