/usr/share/php/Horde/ is in php-horde-sessionhandler 2.2.3-1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/php/Horde/SessionHandler/
/usr/share/php/Horde/SessionHandler.php
/usr/share/php/Horde/SessionHandler/Exception.php
/usr/share/php/Horde/SessionHandler/Storage/
/usr/share/php/Horde/SessionHandler/Storage.php
/usr/share/php/Horde/SessionHandler/Storage/Builtin.php
/usr/share/php/Horde/SessionHandler/Storage/External.php
/usr/share/php/Horde/SessionHandler/Storage/File.php
/usr/share/php/Horde/SessionHandler/Storage/Hashtable.php
/usr/share/php/Horde/SessionHandler/Storage/Memcache.php
/usr/share/php/Horde/SessionHandler/Storage/Mongo.php
/usr/share/php/Horde/SessionHandler/Storage/Sql.php
/usr/share/php/Horde/SessionHandler/Storage/Stack.php