CVE-2026-54784 – CoreWCF: SPNEGO SecurityContextToken proof key wrapped without confidentiality

CVE ID :CVE-2026-54784

Published : July 8, 2026, 11:16 p.m. | 31 minutes ago

Description :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.

Severity: 7.4 | HIGH

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