CVE-2026-54781

Summary

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 confirmation method assertions to authenticate a subject without proving authority over the assertion. This issue is fixed in versions 1.8.1 and 1.9.1.

Affected Software

VendorProductVersion RangeStatus
CoreWCFCoreWCF>= 1.9.0, < 1.9.1affected
CoreWCFCoreWCF< 1.8.1affected

Weaknesses

  • CWE-287: CWE-287: Improper Authentication
  • CWE-345: CWE-345: Insufficient Verification of Data Authenticity

References