The Apache Hadoop PMC has released version 3.0.0-alpha3.
This is a security release in the 3.0.0 release line. It consists of alpha2 plus security fixes, along with necessary build-related fixes. Users on 3.0.0-alpha1 and 3.0.0-alpha2 are encouraged to upgrade to 3.0.0-alpha3.
More information about the vulnerability will be forthcoming in another announcement.
Please note that alpha releases come with no guarantees of quality or API stability, and are not intended for production use.
The quite minimal CHANGES and RELEASENOTES can be viewed here: