Today, Apple released a round of security updates for its operating systems, including iOS 10.3.3, macOS 10.12.6 Sierra, watchOS 3.2.3, and tvOS 10.2.2. It also, however, updated its apps on Windows, which include iTunes 12.6.2 and iCloud 6.2.2.
iTunes 12.6.2 fixes an issue that could allow an application to "execute arbitrary code with system privileges", and other than that, the other seven fixed vulnerabilities are the same between the two apps. One of those has to do with libxml2, and the other six are all WebKit, WebKit Page Loading, and WebKit Web Inspector.
Most of the items listed can be found in the OS updates that the company also released today. You can find the full changelog for iTunes 12.6.2 here and iCloud 6.2.2 here.
As with all security updates, it's recommended that you install these as soon as you can. You should be able to update both iTunes and iCloud through the Apple Software Update app on Windows.
