Nokia C5-03 firmware updatedto version 12.0.23. Its previous software version wasv 11.0.024.
You can update your Nokia C5-03 firmware over OTA (Over-The-Air) or via Nokia’s Software Updater application, Ovi Suite on Windows PC . The Nokia C5-03 does have UDP (User Data Preservation), but its always a good idea to backup all your personal data before updating the firmware.
It may take some time before the new firmware is available for your region.
Official Changelog is still unknown, Will update the post as we get it!
In the mean time do let us know if you find any thing new in this update.