/usr/share/doc/libcupt3-dev/changelog.gz is in libcupt3-dev 2.6.4.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/libcupt3-dev/../libcupt3-0/changelog.gz
/usr/share/doc/libcupt3-dev/../libcupt3-0/changelog.gz