The present disclosure involves systems, software, and computer implemented methods for sharing session state between portal application portlets associated with different domains. One example method includes setting a cookie for use in a portal environment. The cookie is encrypted with a key and stores at least a portion of a session state associated with a current portal session. The encrypted cookie is provided for storage at a client associated with the portal session. Execution of a portal application is initiated within the portal environment. The portal application is provided with a copy of the encrypted cookie. A copy of the key is provided to the portal application. The provided copy of the key is used to decrypt the cookie at the portal application. The session state stored in the cookie is used to set at least a portion of the session state of the portal application.