Vulnerability in Corewcf
CVE-2026-54782
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.
EPSS: 0.002 (16.2th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 10.0 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N.
Affected products
- Corewcf — versions >= 1.9.0, < 1.9.1, < 1.8.1
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-54782?
- CVE-2026-54782 is a critical-severity vulnerability in Corewcf, classified under Authentication Bypass by Spoofing. CVSS score: 10.0/10. Published 2026-07-08.
- How severe is CVE-2026-54782?
- Critical severity. CVSS v3 base score is 10.0 out of 10.