This major release comes with a blog post about a CVE:

    https://www.keycloak.org/2021/12/cve.html

Not all versions are affected but they're suggesting that people upgrade soon.

As per usual, this upgrade didn't go too smoothly and I ended up having to
undeploy and deploy the new versions. The healtcheck kept failing on the new
instance when trying to deploy alongside the existing old version. Idk, some
docker weirdness.

No app data errors discovered after upgrade.