What is this rapid security response 16.4.1 (a)

[chiawen.yang]

Received an update for rapid security response 16.4.1 (a).

What is this about? It was a very quick reboot update.

 

[Nermal]

Apple has, as far as I'm aware, not yet documented that update.

 

[chiawen.yang]

Apple has, as far as I'm aware, not yet documented that update.

Ahh, I clicked on it wanting to know more info and thought was a bug that no knowledge base was shown for the update. Guess it was too sensitive to let the public know what it was about.