CVE-2026-54784

Summary

CoreWCF is a port of the service side of Windows Communication Foundation (WCF) to .NET Core. In version 1.9.0, CoreWCF SPNEGO SecurityContextToken negotiation can expose the proof key recovered from the RSTR when TransportWithMessageCredential with Windows client credentials and session establishment are used, allowing an observer to impersonate the authenticated Windows principal and decrypt or forge WS-SecureConversation traffic. This issue is fixed in version 1.9.1.

Affected Software

VendorProductVersion RangeStatus
CoreWCFCoreWCF>= 1.9.0, < 1.9.1affected

Weaknesses

  • CWE-311: CWE-311: Missing Encryption of Sensitive Data
  • CWE-523: CWE-523: Unprotected Transport of Credentials

References