High 7.4Published Jul 8, 2026

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

Updated under an hour ago (Oct 27, 2026, 10:00 PM ET)

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It affects CoreWCF. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for CoreWCF

Exploited in the last 30 days

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.

CVSS: 7.4 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Weakness (CWE): CWE-311, CWE-523
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Deferred
Record last updated: Jul 9, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

CoreWCF CoreWCF corewcf:corewcf (from the name)	from 1.9.0, < 1.9.1	CNA record

References

References

https://github.com/CoreWCF/CoreWCF/security/advisories/GHSA-2288-8h3r-cqgg	x-refsource-confirm
https://github.com/CoreWCF/CoreWCF/commit/2afae08b2fa5288428df89e8161116b816cf6b4b	x-refsource-misc
https://github.com/CoreWCF/CoreWCF/commit/f216aa6929d41dc99cee098b1e69c260ec4c41c7	x-refsource-misc
https://github.com/CoreWCF/CoreWCF/releases/tag/v1.9.1	x-refsource-misc

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.