SP ODU firmware ver. 27 is available below and is suggested for all SP ODUs running with GigaPlus or GigaPro.
Follow the detailed instructions in the release notes to copy the file to the radio and then issue the bootimage upgrade odu command. If you're doing this on a live link, it will cause link loss while the firmware is updated. This firmware will still work with Giga, so there should be no concern with cross compatibility.
After upgrade the firmware version should show 27. You may have to reboot the IDU or power cycle the ODU again to get the version displayed to update.