Disclosed is a method for protecting a single sign-on domain from credential leakage. In the method, an authentication server provides an authentication cookie to a browser client. The cookie has at least one user authentication credential for the domain, and is associated with an authentication subdomain of the domain. The server receives the cookie from the browser client. Upon authentication of the user authentication credential in the received cookie, the server responds to the access request by forwarding, to the browser client, a limited-use cookie for the domain. The server receives a request from the content server to validate a session identifier of the limited-use cookie received from the browser client. Upon validation of the session identifier of the limited-use cookie, the server provides a valid session message to the content server for enabling the content server to forward requested content to the browser client.