/usr/lib/x86_64-linux-gnu/libmunge.so is in libmunge-dev 0.5.13-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libmunge.so.2.0.0
/usr/lib/x86_64-linux-gnu/libmunge.so.2.0.0