Zimbra can be updated using apt update or yum update, and it is highly recommended to install Zimbra updates (patches) as they are released, especially in case of patches that include security fixes.
Here are a few ways to stay informed on Zimbra Security updates:
Subscribe to these RSS feeds:
- https://wiki.zimbra.com/security-advisory-feed.php (no details, can be used for security notification purposes)
- https://blog.zimbra.com/feed/ (includes patches and security news with details and other news)
You can manually check this page: https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories
Or subscribe to the Zeta Alliance mailing lists: https://lists.zetalliance.org/mailman/listinfo/users_lists.zetalliance.org