To download the update, go to Settings > General > Software Update, tap Install Now and follow the onscreen prompts. 

Apple's update addresses an issue that causes some iPhone 15 features, like Apple Pay, to not work after wireless charging in some vehicles. The update also addresses an issue that causes the Weather lock screen widget to not correctly show the symbol for snow.

While some iPhone users said on X, formerly Twitter, that the update appeared to cause their device's battery to drain, and it was the topic of a discussion on Reddit, it's not clear if it's a widespread issue. CNET has contacted Apple for comment. However, Apple has previously said this isn't unusual and it can take up to 48 hours for your iPhone's apps and features to adjust to a new update.

Here are Apple's release notes for iOS 17.1.1:

This update provides bug fixes for your iPhone including:

• In rare circumstances, Apple Pay and other NFC features may become unavailable on iPhone 15 models after wireless charging in certain cars.

• Weather Lock Screen widget may not correctly display snow.

Apple is expected to release iOS 17.2 soon. That update could include long-awaited features like the Journal app and Contact Key Verification.