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CVE

CVE-2026-54782

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

CVE-2026-54782

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

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.

Package Versions Affected

Package Version
patch Availability
No items found.

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CVSS Version

Severity
Base Score
CVSS Version
Score Vector
C
H
U
10
-
3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N
C
H
U
0
-
3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N
C
H
U
10
-
3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N

Related Resources

No items found.

References

https://github.com/CoreWCF/CoreWCF/releases/tag/v1.8.1, https://github.com/CoreWCF/CoreWCF/releases/tag/v1.9.1, https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/54xxx/CVE-2026-54782.json, https://github.com/CoreWCF/CoreWCF/security/advisories/GHSA-xjr9-gg9q-jx3v, https://nvd.nist.gov/vuln/detail/CVE-2026-54782, https://github.com/CoreWCF/CoreWCF/commit/0b8c8af851260e85e8402af53233d1b8f87dfb6f, https://github.com/CoreWCF/CoreWCF/commit/0e63c2cca55763d8be6b226a234579280a09e7b6, https://github.com/CoreWCF/CoreWCF/commit/e5cc9b6a4ecc102a50d782093bfc72e0790abe3d

Severity

10

CVSS Score
0
10

Basic Information

Base CVSS
10
EPSS Probability
0.00414%
EPSS Percentile
0.35243%
Introduced Version
0
Fix Available
e5cc9b6a4ecc102a50d782093bfc72e0790abe3d

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