Student educational records are considered confidential and may not be released without the written consent of the student.
As a faculty or staff member you have a responsibility to protect educational records in your possession.
Some information is considered public (sometimes called "Directory Information"). This information can be released without the student's written permission. However, the student may opt to consider this information confidential as well.
You have access to information only for legitimate use in completion of your responsibilities as a university employee. Need to know is the basic principle.
If you are ever in doubt, do not release any information until you contact your School registrar. Your School registrar is responsible for student record information.