My installed iTunes v12.13.3.2 just told me v12.13.4.4 is out in my updated 64-bit W10 Pro. PC.
However, I can't find any information on what is fixed and new though. :/
Apple sometimes detail security updates with a new release, and new releases may sometimes be required to support newer versions of iOS. These are the notes on the previous build: About the security content of iTunes 12.13.3 for Windows - Apple Support. I cannot as yet locate a parallel document for 12.13.4.4.
tt2