Update to macOS 10.14.5 for “ZombieLoad” vulnerability fix and Airplay 2 support:

Info
https://www.macworld.com/article/3394579/

Update
https://support.apple.com/kb/DL2001?locale=en_US

More information on the patch, unsupported models, and additional mitigation instructions (if necessary) available from Apple. For most user’s the 10.14.5 patch will suffice, at least in the near term.

https://support.apple.com/en-us/HT210107