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CVE-2026-54781

CoreWCF: SAML SubjectConfirmation methods and holder-of-key proof keys are not enforced

Published: Jul 8, 2026Updated: Jul 9, 2026 Sources: CVE List NVDCWE-287
7.4HIGH
NVD MITRE
EPSS Score
0.2%
Top 92.5%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
No Fix Available
Self-Check
Not available

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, CoreWCF SAML token validation does not enforce SubjectConfirmation method URIs or holder-of-key proof keys in SamlSecurityTokenHandler, allowing holder-of-key downgrade or custom confirmation method assertions to authenticate a subject without proving authority over the assertion. This issue is fixed in versions 1.8.1 and 1.9.1.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:HPR:NUI:NS:UC:HI:HA:N
Exploitability
AV:NAttack Vector
Network
AC:HAttack Complexity
High
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:HConfidentiality
High
I:HIntegrity
High
A:NAvailability
None
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Weaknesses

CWE-287CWE-345

Affected Products

CoreWCF
oss-project
CoreWCFLibrary
OSS Libraries / web-framework

Exploitability

No known exploits, KEV entries, or remediation guidance available for this vulnerability yet.
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Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

3 techniques
Collection
Initial Access
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References

https://github.com/CoreWCF/CoreWCF/security/advisories/GHSA-48pq-2xq3-c2m4
github.com
https://github.com/CoreWCF/CoreWCF/commit/6a99df3242f54acd6f89edfd6050430b72d0c685
github.com
https://github.com/CoreWCF/CoreWCF/commit/86dd3232b6b8aaf32281be9e8d798afad6145d58
github.com
and 3 more references View all →

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