Passport-wsfed-saml2 is a ws-federation protocol and SAML2 tokens authentication provider for Passport. In versions prior to 4.6.3, a remote attacker may be able to bypass WSFed authentication on a website using passport-wsfed-saml2. A successful attack requires that the attacker is in possession of an arbitrary IDP signed assertion. Depending on the IDP used, fully unauthenticated attacks (e.g without access to a valid user) might also be feasible if generation of a signed message can be triggered. This issue is patched in version 4.6.3. Use of SAML2 authentication instead of WSFed is a workaround.