Zikula Core 1.3.6 is released as of November 6, 2013. This is strictly a security release for the Core 1.3.x series. All users of Core 1.3.0 - 1.3.5 are recommended to update as soon as possible. This release does not contain any other bug fixes or features over Core 1.3.5.
Installation/Upgrade: (from Core 1.3.5) simply overwrite the files in your current installation with the new files run the upgrade.php routine.
Download:
The release that was to be version 1.3.6 has been renamed to 1.3.7 and is yet unreleased. Please adjust your development module dependencies accordingly.