CVE-2026-54784

CoreWCF: SPNEGO SecurityContextToken proof key wrapped without confidentiality

Published Jul 8, 2026 CVSS 3.1 · 7.4 High EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-2288-8h3r-cqgg CoreWCF: SPNEGO SecurityContextToken proof key wrapped without confidentiality
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Corewcf
Corewcf corewcf
Vendors & Products Corewcf
Corewcf corewcf
Type Values Removed Values Added
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.
Title CoreWCF: SPNEGO SecurityContextToken proof key wrapped without confidentiality
Weaknesses CWE-311
CWE-523
References
Metrics cvssV3_1

{'score': 7.4, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Jul 10, 2026, 3:55 AM
Reserved
Jun 15, 2026, 11:23 PM
Status
Deferred
Published
Jul 8, 2026, 11:16 PM
Modified
Jul 10, 2026, 5:16 AM