When executing a shell command like ssh to connect to a server (with ssh credentials plugin v1.11), the connection fails with:

09:36:59 Authorized uses only. All activity may be monitored and reported.
09:36:59 Permission denied, please try again.
09:36:59 Permission denied, please try again.
09:36:59 Received disconnect from xx.xx.xx.xx: 2: Too many authentication failures for xxx
09:36:59 lost connection
09:36:59 Build step 'Execute shell' marked build as failure
09:36:59 [ssh-agent] Stopped.

After downgrading to version 1.10 everything works fine.