/usr/lib/ghc-doc/hoogle/libghc-xss-sanitize-doc.txt is in libghc-xss-sanitize-doc 0.3.5.7-3build7.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-xss-sanitize-doc/html/xss-sanitize.txt