CVE-2026-54774
Published:July 08, 2026
Updated:July 21, 2026
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.
Affected Packages
corewcf.primitives (DOT_NET):
Affected version(s) >=0.1.0.8 <1.8.1Fix Suggestion:
Update to version 1.8.1https://github.com/CoreWCF/CoreWCF.git (GITHUB):
Affected version(s) =v1.9.0 <v1.9.1Fix Suggestion:
Update to version v1.9.1https://github.com/CoreWCF/CoreWCF.git (GITHUB):
Affected version(s) >=v0.3.0 <v1.8.1Fix Suggestion:
Update to version v1.8.1corewcf.primitives (NUGET):
Affected version(s) =1.9.0 <1.9.1Fix Suggestion:
Update to version 1.9.1corewcf.primitives (NUGET):
Affected version(s) >=0.1.0-preview <1.8.1Fix Suggestion:
Update to version 1.8.1Related Resources (7)
Do you need more information?
Contact UsCVSS v4
Base Score:
9.1
Attack Vector
NETWORK
Attack Complexity
HIGH
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
HIGH
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
7.4
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
NONE
Weakness Type (CWE)
EPSS
Base Score:
0.15