CVE-2026-54782

CRITICAL

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

Title source: cna
STIX 2.1

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.

References (6)

Core 6

Scores

CVSS v3 10.0
EPSS 0.0025
EPSS Percentile 16.0%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact total

Details

CWE
CWE-290 CWE-347
Status published
Products (2)
CoreWCF/CoreWCF < 1.8.1
CoreWCF/CoreWCF >= 1.9.0, < 1.9.1
Published Jul 08, 2026
Tracked Since Jul 09, 2026