/usr/lib/python2.7/dist-packages/customfieldadmin/templates/customfieldadmin.html is in trac-customfieldadmin 0.2.6+r10460-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/python2.7/dist-packages/customfieldadmin/templates/../../../../../share/pyshared/customfieldadmin/templates/customfieldadmin.html