CVE-2026-54774
High
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.
SeverityHigh
CVSS7.4
Exploit probability—
ProductCorewcf.primitives
PublishedJul 8, 2026
First seenJul 8, 2026
Weakness typeCWE-345CWE-345CWE-347CWE-347
How to fix
Update
- CoreWCF.Primitives1.8.1, 1.9.1 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| CoreWCF.PrimitivesNuGet | v < 1.8.1, 1.9.0 ≤ v < 1.9.1 | 1.8.1, 1.9.1 |
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