The latest update to macOS High Sierra is now available for all customers. The new build ships with version 17D47 or 17D2047 depending on your machine.
The new version is available on Apple’s developer center and is rolling out to all users now. Release notes for the new software update specifically call out a fix for Messages:
The macOS High Sierra 10.13.3 update improves the security and stability of your Mac, and is recommended for all users.
This update addresses an issue that could cause Messages conversations to temporarily be listed out of order.
The update comes in at a relatively small 1.97GB (on my iMac). Developers and public beta testers should not need to update from the last beta version.
In addition to the release notes, Apple has published these details about the security changes:
This update is recommended for all macOS High Sierra users.
The macOS High Sierra 10.13.3 Update improves the stability and security of your Mac and is recommended for all users.
Addresses an issue that could cause Messages conversations to temporarily be listed out of order
Resolves an issue that could cause your Mac to stop responding when connected to an SMB server