CVE-2026-54781 CoreWCF: SAML SubjectConfirmation methods and holder-of-key proof keys are not enforced

CoreWCF is a port of the service side of Windows Communication Foundation WCF to .NET Core. Prior to 1.8.1 and 1.9.1, CoreWCF SAML token validation does not enforce SubjectConfirmation method URIs or holder-of-key proof keys in SamlSecurityTokenHandler, allowing holder-of-key downgrade or custom...