Insufficient Session Expiration Affecting corewcf.primitives package, versions [1.0.0-preview1,1.8.1)[1.9.0,1.9.1)
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Test your applications- Snyk IDSNYK-DOTNET-COREWCFPRIMITIVES-17391909
- published21 Jun 2026
- disclosed19 Jun 2026
- creditUnknown
Introduced: 19 Jun 2026
NewCVE-2026-54779 (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 Session Expiration due to the TryAdd implementation in DefaultTokenReplayCache. An attacker can bypass replay detection by resubmitting the same SAML token, causing the cache to accept duplicate entries and letting replayed assertions be processed as fresh. This allows repeated use of a captured token to impersonate a user or reuse an authenticated session, undermining the protection expected from replay checking.