The latest update carries firmware version CPH2159_11_A.25 and requires 738MB of your internet data. It’s quite surprising to see such a bulky update that only brings a new security patch. Security patch updates are important for devices as it fixes different kinds of exploits to improve the device security. Therefore, it is always recommended to keep your device updated with the latest security patch available.
If you’re an Oppo Reno5 4G user then you would have already received the April 2021 security update. If not, then manually check for the update by navigating to Settings » Software updates. [via]