CVE-2026-54774
CoreWCF: SamlSerializer skips SignatureValue verification when SAML signing token is not an X.509 certificate
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.
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-2026-54774
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 | HIGH | [email protected] |
Solution
- Update CoreWCF to version 1.8.1 or 1.9.1.
- Ensure SAML tokens are validated correctly.
- Configure proper X.509 signing tokens.
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-2026-54774.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-54774 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-2026-54774
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-2026-54774 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-54774 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, 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. Added CVSS V3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N Added CWE CWE-345 Added CWE CWE-347 Added Reference https://github.com/CoreWCF/CoreWCF/commit/65d09022749854ba943e376aefb958dec05b00d8 Added Reference https://github.com/CoreWCF/CoreWCF/commit/b914495ce63c44924664643b60a262e7595081a4 Added Reference https://github.com/CoreWCF/CoreWCF/commit/e7454132876ecc7e2cf80e541a44376eeb54979b 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-rpj7-hr7h-w6p9