Apple has used the Apple Rapid Security Response feature of iOS and macOS for the first time, since it was included with the operating systems seven months ago, to send a patch to the public.
Apple uses iOS and macOS Rapid Security Response feature for the first time | Ars Technica
However all did not go well with the first issue of the patch failing to install on some devices.
Apple has not commented on exactly what vulnerability the emergency patch was to address. These out of band updates were intended to address flaws that are being actively or could be exploited threat actors. Best to make sure that your devices are patched and check that any other affected devices across your organisation are also patched.
Clive Catton MSc (Cyber Security) – by-line and other articles