/usr/lib/x86_64-linux-gnu/libjansson.so is in libjansson-dev 2.7-3ubuntu0.1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libjansson.so.4.7.0
/usr/lib/x86_64-linux-gnu/libjansson.so.4.7.0