CVE-2026-54784
CoreWCF: SPNEGO SecurityContextToken proof key wrapped without confidentiality
CVSS Score
7.4
EPSS Score
0.2%
EPSS Percentile
7th
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.
| CWE | CWE-311 CWE-523 |
| Vendor | corewcf |
| Product | corewcf |
| Published | Jul 8, 2026 |
| Last Updated | Jul 10, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None
Affected Versions
CoreWCF / CoreWCF
>= 1.9.0, < 1.9.1
References
github.com: https://github.com/CoreWCF/CoreWCF/security/advisories/GHSA-2288-8h3r-cqgg github.com: https://github.com/CoreWCF/CoreWCF/commit/2afae08b2fa5288428df89e8161116b816cf6b4b github.com: https://github.com/CoreWCF/CoreWCF/commit/f216aa6929d41dc99cee098b1e69c260ec4c41c7 github.com: https://github.com/CoreWCF/CoreWCF/releases/tag/v1.9.1