Attempting to use eap6.1 jboss-cli.sh to connect to remote wildfly (alpha1 or 2) fails; credentials not accepted

Using eap6.1 client jars, or the jboss-cli.sh script in a local eap6.1 installation, to connect to a remote wildfly alpha1 or alpha2, seems to work but fails when provided with credentials. This is most easily replicated as follows:

1) On remote machine start wildfly alpha1 or alpha2
2) on local machine, cd eap-6.1/bin
3) on local machine:

[rob@rawbdor bin]$ ./jboss-cli.sh
You are disconnected at the moment. Type 'connect' to connect to the server or 'help' for the list of supported commands.
[disconnected /] connect myhost.net
Authenticating against security realm: ManagementRealm
Username: admin
Password:
Unable to authenticate against controller at myhost.net:9999: Authentication failed: all available authentication mechanisms failed

This is an issue for tools as we need a set of jars that communicates correctly with all as7 servers. We currently have a set of jars that communicates with all 7.x / eap 6.x, which is good. If this is merely a bug on the server, then we can hopefully delay having to bundle an additional set of client jars until larger breakages occur.