Qt 5.9.8 release is the eighth patch release from the series has been announced and it comes with a number of bug fixes and other improvements.
You can find a comprehensive list of changes from the official release page here which includes updates to some of the 3rd party modules and over 20 bug fixes.
Qt 5.9.8 release is available for the update using the maintenance tool of the online installer. If you do not have it you can grab a copy from the Qt download page here.
Commercial users can upgrade from the account portal here.