You will not need to update the Firepower Management Center OS Software, rather you will need to update the Vulnerability Database(VDB). This bug is marked as resolved in VDB 290 so please update your VDB on the FMC above 290  

Haitham, The ASA stores a local cache of recent malware lookups in the event that we see a file more than one time. The local cache is checked prior to looking the SHA up against the cloud. Any cloud lookups that occur we add the disposition receive...

Good morning, The Cloud Malware Lookup does lookup the HASH of the file against the cloud, however, it does not wait for the response from the Cloud API, rather it simply sends the file on its way and reports the disposition back in the file event. ...