The Qt developers announced on their blog about the release of Qt 5.9.3, which is a patch and does not bring anything new in terms of functionality. However, it focused on fixing bugs and improving performance.
Compared to Qt 5.9.2. Qt 5.9.3 has fixed over 100 bugs and made over 500 changes. To get acquainted with the changes you can follow the link .
The Qt 5.9.3 release also contains security fixes, including two vulnerabilities in the Android version .
The Qt developers intend to patch Qt 5.9 LTS as often as possible. And Qt 5.9.4 is scheduled for January 2018, and will receive the next set of fixes.
Anyone using the online installer can upgrade to Qt 5.9.3 using the maintenance tool. Offline installers are available for commercial users at Qt Account portal , as well as at download page for users of versions with open source.
In addition to updating to Qt 5.9.3, we can also update Qt Creator to version 4.5 RC.