Ian Beer has tweeted that he will be releasing an exploit that will work for iOS 11.1.2 or lower like iOS 11.0.1, 11.0.2, 11.0.3, 11.1 or 11.1.1.
If you're interested in bootstrapping iOS 11 kernel security research keep a research-only device on iOS 11.1.2 or below. Part I (tfp0) release soon.— Ian Beer (@i41nbeer) December 5, 2017
Why you should Jailbreak your iPhone
That means before it’s too late, downgrade your iPhone or iPad to iOS 11.1.2 or lower and wait for a jailbreak release.
How to downgrade your iPhone or iPad to iOS 11.1.2/11.1.1 or below from iOS 11.2