Apple has released extensive security updates. They mainly fix security gaps, so you should update as soon as possible. According to Apple, the gaps have already been exploited and relate to browser security, for example.
Available are not only iOS and iPadOS 16.5 but also watchOS 9.5, tvOS 16.5 and new HomePod software. For Mac, macOS 13.4 is available. Those still on the older system can install Big Sur 11.7.7 and Monterey 12.6.6. Safari 16.5 is also offered for update here.