CVE-2026-54782
CoreWCF: Authentication bypass in CoreWCF SAML 1.1 / 2.0 token signature validation
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.
INFO
Published Date :
July 8, 2026, 11:16 p.m.
Last Modified :
July 8, 2026, 11:16 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-54782
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | CRITICAL | [email protected] |
Solution
- Update CoreWCF to version 1.8.1 or later.
- Update CoreWCF to version 1.9.1 or later.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-54782.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-54782 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-54782
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-54782 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-54782 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Jul. 08, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'CoreWCF', 'product': 'CoreWCF', 'versions': [{'status': 'affected', 'version': '>= 1.9.0, < 1.9.1'}, {'status': 'affected', 'version': '< 1.8.1'}]}] Added 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. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N Added CWE CWE-347 Added CWE CWE-290 Added Reference https://github.com/CoreWCF/CoreWCF/commit/0b8c8af851260e85e8402af53233d1b8f87dfb6f Added Reference https://github.com/CoreWCF/CoreWCF/commit/0e63c2cca55763d8be6b226a234579280a09e7b6 Added Reference https://github.com/CoreWCF/CoreWCF/commit/e5cc9b6a4ecc102a50d782093bfc72e0790abe3d Added Reference https://github.com/CoreWCF/CoreWCF/releases/tag/v1.8.1 Added Reference https://github.com/CoreWCF/CoreWCF/releases/tag/v1.9.1 Added Reference https://github.com/CoreWCF/CoreWCF/security/advisories/GHSA-xjr9-gg9q-jx3v