We setup Jenkins with the "Mask Passwords Plugin".
We setup jobs with masked password parameters.

If we open such a job with IE11, the masked password fields are shown empty. The job/..../config.xml in the filesystem shows the correct masked entry. A different browser, e.g. IE9/Chrome show a masked password.

If a save the job with IE11, a corrupted (shorter) masked password is stored (I checked in the config.xml).

If the job is executed, it fails - the password parameter contains an incorrect value.

This occurs with IE11, IE10 was fine, IE9 is fine, Chrome 31 is fine.