CVE-2026-54774

high

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, SamlSerializer skips final SignatureValue verification when a CoreWCF service validates SAML tokens using a non-X.509 signing token, allowing an attacker to reference a non-X.509 SecurityToken key identifier and bypass assertion signature verification. This issue is fixed in versions 1.8.1 and 1.9.1.

References

https://github.com/CoreWCF/CoreWCF/security/advisories/GHSA-rpj7-hr7h-w6p9

https://github.com/CoreWCF/CoreWCF/releases/tag/v1.9.1

https://github.com/CoreWCF/CoreWCF/releases/tag/v1.8.1

https://github.com/CoreWCF/CoreWCF/commit/e7454132876ecc7e2cf80e541a44376eeb54979b

https://github.com/CoreWCF/CoreWCF/commit/b914495ce63c44924664643b60a262e7595081a4

https://github.com/CoreWCF/CoreWCF/commit/65d09022749854ba943e376aefb958dec05b00d8

Details

Source: Mitre, NVD

Published: 2026-07-08

Updated: 2026-07-10

Risk Information

CVSS v2

Base Score: 7.1

Vector: CVSS2#AV:N/AC:H/Au:N/C:C/I:C/A:N

Severity: High

CVSS v3

Base Score: 7.4

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Severity: High

EPSS

EPSS: 0.0015