Oracle Integration Classic (user-managed) only provides maintenance fixes on top of the latest software release. Therefore, when a software upgrade is available at the beginning of a month, it is your responsibility to manually upgrade any existing Oracle Integration Classic instances to the latest release by applying software upgrade patches. If you are not on the latest release, you must patch your instance to be at the latest software release before you can apply any additional maintenance fixes. For example, if you provisioned Oracle Integration Classic 17.4.1, and there have been several software upgrades since then, you must first upgrade to the latest software release before you can apply any additional maintenance fixes. Note that the latest software release patch always includes the previous software releases. Therefore, you only need to apply that single patch to be upgraded to the latest release.
This situation does not apply to newly provisioned instances. For Oracle Integration Classic instances that are provisioned after the maintenance fixes are announced and available, they are automatically applied and available in the newly provisioned instance.
For information about applying patches from the Oracle Integration Classic Oracle Cloud Infrastructure Console, see Patch and Upgrade Oracle Integration Classic (User-Managed).