The super POM defines version 2.3.2 of the Maven Release plugin. When using HTTP/HTTPS Git SCM URIs, Maven will printout the password in the logs. Thus, any CI system such as Jenkins, TravisCI, etc. will have the passwords exposed in the logs and in the console output. In the case of TravisCI, this will be publicly visible.
The Maven Release Plugin fixed this issue in MRELEASE-846, but Maven core is still pointing at an exposed version of the Maven Release plugin. I have a test case that demonstrates the issue here:
If you run the same build and explicitly define 2.5.3, the password is no longer displayed. This should be the default.