Currently: "//All data in the (Wikimedia commons) Data: namespace must be in Public Domain, licensed under Creative Commons Zero (CC0) license. To indicate this, every data page must have "license": "CC0-1.0", which means the data can be used under the CC0 version 1.0, or (at your option) any later version. By editing the data, you agree to the Terms of Use, and you irrevocably agree to release your contribution to the public domain under CC0. At some future time, the list of licenses supported by the Data namespace may be expanded.//". per https://www.mediawiki.org/wiki/Help:Map_Data
However it would be practical to be able to use data from Openstreetmap . Also in Finland where i live goverment licence for their open data is CC-BY (including map data) and it would be nice to be able to use that too.