freecad included non-free content.
See: https://lintian.debian.org/tags/license-problem-cc-by-nc-sa.html (freecad Section).
This files license is cc-by-nc-sa.
It is non-free.
Has upstream been informed?
These files are not CC-BY-NC-SA, I have no idea why Debian's lintian flagged them as such.
edit-cut.svg is taken from the Tango Icons theme, which was once CC-BY-SA and is now in the Public Domain:
mesh_cut.svg is clearly derived from edit-cut.svg:
There is no evidence of this file being licensed CC-BY-NC-SA, in fact, because the original work is Public Domain, their "artwork license declaration would apply", making it LGPL:
Closing as NOTABUG.