I use the release plugin setting the credentials for my git repository in the settings.xml file. If I have a password without spaces it works but if it has spaces it doesn't.
With Maven Release Plugin 2.3.2 it used to work without an issue.
In the log of the maven execution I see that 2.3.2 used to encode the spaces in passwords as %20 but 2.5.1 does encode them as +. Not sure if this is relevant as I think both encodings are supposed to be good, but just in case.