CVE-2026-54784 Details
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.
A vulnerability in CoreWCF version 1.9.0 allows the SPNEGO SecurityContextToken proof key to be transmitted without confidentiality. This issue arises when using TransportWithMessageCredential security mode with Windows client credentials and session establishment, which activates WS-SecureConversation. The flaw enables a passive network observer to intercept the proof key from the RSTR, impersonate the authenticated Windows principal for the duration of the SCT, and manipulate WS-SecureConversation traffic by decrypting or forging messages. The vulnerability is present in CoreWCF.Primitives package version 1.9.0.
Users can upgrade to CoreWCF version 1.9.1, which addresses this vulnerability by ensuring that the proof key is encrypted before transmission. Instructions for upgrading can be found in the CoreWCF release notes.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Jul 8, 2026CISA-ADP
Assessed Jul 9, 2026References to Advisories, Solutions, and Tools
By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.
| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/CoreWCF/CoreWCF/commit/2afae08b2fa5288428df89e8161116b816cf6b4b | [email protected] | Source CodeVendor |
| https://github.com/CoreWCF/CoreWCF/commit/f216aa6929d41dc99cee098b1e69c260ec4c41c7 | [email protected] | Source CodeVendor |
| https://github.com/CoreWCF/CoreWCF/releases/tag/v1.9.1 | [email protected] | Release NotesVendor |
| https://github.com/CoreWCF/CoreWCF/security/advisories/GHSA-2288-8h3r-cqgg | [email protected] | AdvisoryRemedyVendor |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-311 | Missing Encryption of Sensitive Data | [email protected] |
| CWE-523 | Unprotected Transport of Credentials | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| CoreWCF | 1.9.0 (semver) |
CPE
Remediation
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| CoreWCF.ConfigurationManager | All versions |
CPE
Remediation
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| CoreWCF.Http | All versions |
CPE
Remediation
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| CoreWCF.Kafka | All versions |
CPE
Remediation
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| CoreWCF.Kafka.Client | All versions |
CPE
Remediation
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| CoreWCF.MSMQ | All versions |
CPE
Remediation
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| CoreWCF.NetFramingBase | All versions |
CPE
Remediation
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| CoreWCF.NetNamedPipe | All versions |
CPE
Remediation
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| CoreWCF.NetTcp | All versions |
CPE
Remediation
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| CoreWCF.Primitives | All versions |
CPE
Remediation
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| CoreWCF.Queue | All versions |
CPE
Remediation
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| CoreWCF.RabbitMQ | All versions |
CPE
Remediation
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| CoreWCF.RabbitMQ.Client | All versions |
CPE
Remediation
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| CoreWCF.Templates | All versions |
CPE
Remediation
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| CoreWCF.UnixDomainSocket | All versions |
CPE
Remediation
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| CoreWCF.WebHttp | All versions |
CPE
Remediation
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Change History
3 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 10, 2026 | CVE Modified | CISA-ADP |
| Jul 9, 2026 | CVE Modified | CISA-ADP |
| Jul 8, 2026 | New CVE Received | [email protected] |