Unprotected Transport of Credentials Affecting corewcf.primitives package, versions [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-17391881
- published21 Jun 2026
- disclosed19 Jun 2026
- creditUnknown
Introduced: 19 Jun 2026
NewCVE-2026-54784 (opens in a new tab)How to fix?
Upgrade CoreWCF.Primitives to version 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 Unprotected Transport of Credentials through the Encrypt method in CoreWCF.Security.NegotiateInternal.NTAuthenticationNet8. An attacker can recover the SecurityContextToken proof key by passively observing the WS-Trust RSTR on a non-TLS connection, because the wrapped proof key is emitted in cleartext inside the base64-encoded response. With that symmetric session key, the attacker can impersonate the authenticated Windows principal for the lifetime of the SCT and use the victim’s established security context.