CVE-2026-54774

CoreWCF: SamlSerializer skips SignatureValue verification when SAML signing token is not an X.509 certificate

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. Prior to 1.8.1 and 1.9.1, SamlSerializer skips final SignatureValue verification when a CoreWCF service validates SAML tokens using a non-X.509 signing token, allowing an attacker to reference a non-X.509 SecurityToken key identifier and bypass assertion signature verification. This issue is fixed in versions 1.8.1 and 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-rpj7-hr7h-w6p9 CoreWCF: SamlSerializer skips SignatureValue verification when SAML signing token is not an X.509 certificate
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. Prior to 1.8.1 and 1.9.1, SamlSerializer skips final SignatureValue verification when a CoreWCF service validates SAML tokens using a non-X.509 signing token, allowing an attacker to reference a non-X.509 SecurityToken key identifier and bypass assertion signature verification. This issue is fixed in versions 1.8.1 and 1.9.1.
Title CoreWCF: SamlSerializer skips SignatureValue verification when SAML signing token is not an X.509 certificate
Weaknesses CWE-345
CWE-347
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