Personal and work iPhone security OS update completed. Lockdown Mode enabled.
There were geek news site articles, even a mainstream ABC7 news article, saying to apply the most recent iPhone OS update right away, due to zero-day vulnerabilities.
Have to enable wifi on the iPhone first, then can apply the update. For me, the update took about an hour.
Once the update was completed then turned off wifi on the iPhone, as I typically just use mine for voice, texting, and as a camera.
Did the updates on both my personal, and work-issued iPhones.
iPhone Lockdown Mode
With the updates installed, went into Settings, then typed "lockdown" into the Settings' searchbar. Read the documentation on what it does, and then enabled it for all my iPhones.
Once selected and agreed to, it reboots the iPhone into Lockdown Mode. This only takes a minute or so.
Information about Lockdown Mode from the company itself is located at: https://support.apple.com/en-us/HT212650 .