Automated browser downloads + bug ridden FS indexing parsers like KDE Baloo are a serious threat to systems and a really easy way to mount RCEs on desktops.
AFAIK Baloo is disabled by default but I'm not sure. Can you confirm that it is if its not the case? and of course we need to keep an eye out for it on Whonix Stretch.
Can you create a ticket for this please?