MariaDB 5.5.45 is a maintenance release. It includes several bugfixes and updates, including from MySQL 5.5.45. Notable updates include:
XtraDB updated to 5.5.44-37.3
Diffie-Helman modulus increased to 2048 bits (MDEV-8352)
Add mysqlbinlog --binlog-row-event-max-size support (MDEV-8340)
A full list of all changes is in the changelog.
Thanks, and enjoy MariaDB!
https://mariadb.com/kb/en/mariadb/mariadb-5545-release-notes/