Insufficient Verification of Data Authenticity Affecting corewcf.primitives package, versions [1.0.0-preview1,1.8.1)[1.9.0, 1.9.1)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-DOTNET-COREWCFPRIMITIVES-17391911
- published21 Jun 2026
- disclosed19 Jun 2026
- creditUnknown
Introduced: 19 Jun 2026
NewCVE-2026-54781 (opens in a new tab)How to fix?
Upgrade CoreWCF.Primitives to version 1.8.1, 1.9.1 or higher.
Overview
CoreWCF.Primitives is a port of the service side of Windows Communication Foundation (WCF) to .NET Core. The goal of this project is to enable existing WCF services to move to .NET Core.
Affected versions of this package are vulnerable to Insufficient Verification of Data Authenticity through the ValidateToken path in SamlSecurityTokenHandler. An attacker can get identity claims accepted without proving possession of the bound key by sending a SAML assertion with an unrecognized SubjectConfirmationMethod URI or a holder-of-key subject that omits SubjectConfirmationData KeyInfo. The relying party then receives claims that were not properly bound to the sender, allowing unauthorized authentication as the asserted subject.