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OpenAdvisories
Critical · 10.0 CVE-2026-54782 EUVD-2026-42473GHSA-xjr9-gg9q-jx3v

CoreWCF: Authentication bypass in CoreWCF SAML 1.1 / 2.0 token signature validation

Published Jul 8, 2026 · Updated Jul 10, 2026 · Assigned by GitHub_M

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, CoreWCF SAML 1.1 and SAML 2.0 token validation does not correctly resolve the issuer signing key or require signed tokens when IdentityConfiguration is used with federated bindings, allowing an unauthenticated remote attacker to impersonate any principal the trusted STS could issue. This issue is fixed in versions 1.8.1 and 1.9.1.

Affected products

VendorProductAffectedFixed
CoreWCF CoreWCF >= 1.9.0, < 1.9.1, < 1.8.1 —

Affected packages

EcosystemPackageAffectedFixedRecord
NuGet CoreWCF.Primitives < 1.8.1 1.8.1 GHSA-xjr9-gg9q-jx3v
NuGet CoreWCF.Primitives >= 1.9.0, < 1.9.1 1.9.1 GHSA-xjr9-gg9q-jx3v

References