As far as what is new in this release is concerned, according to Apple’s own official changelog, iTunes 12.6.1 for Windows and Mac only adds “minor app and performance improvements” to iTunes software. While Apple hasn’t detailed security fixes for Mac version of this latest iTunes release, the security content page for iTunes 12.6.1 for Windows lists a fix for WebKit vulnerability. This fix is detailed as follows:
Available for: Windows 7 and later
Impact: Processing maliciously crafted web content may lead to arbitrary code execution
Description: Multiple memory corruption issues were addressed with improved memory handling.
CVE-2017-6984: lokihardt of Google Project Zero
To update to latest iTunes 12.6.1 version release on your Windows computer, simply launch Apple Software Update utility on your PC and grab the update from there. Mac users can do the same by launching Mac App Store on their computer first and then getting the latest pending update from under the Updates tab on MAS.
Alternatively, iTunes version 12.6.1 can also be downloaded directly from Apple for both Windows and Mac from apple.com/iTunes/download. While iTunes isn’t available to download from Windows Store yet, at Microsoft’s BUILD conference last week, both Microsoft and Apple announced that iTunes will be available for download directly from Windows Store by Fall this year.