Vulnerability-Lookup

GHSA-XJR9-GG9Q-JX3V

Vulnerability from github – Published: 2026-06-19 20:47 – Updated: 2026-06-19 20:47

Summary

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

Details

Impact

Full impersonation of any principal the trusted STS could have issued an assertion for — including administrative principals when the relying party grants them via SAML claims. Affects both SAML 1.1 and SAML 2.0.

Preconditions

Relying-party service is hosted with WSFederationHttpBinding or WS2007FederationHttpBinding (or any binding that triggers FederatedSecurityTokenManager for issued-token validation), and IdentityConfiguration is wired (UseIdentityConfiguration = true). Attacker can reach the service over the network and knows the trusted STS’s public certificate (public certs are by design discoverable).

Patches

Fixed in CoreWCF v1.8.1 and v1.9.1

Workarounds

None

Severity

10.0 (Critical)


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

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "NuGet",
        "name": "CoreWCF.Primitives"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.8.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "NuGet",
        "name": "CoreWCF.Primitives"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.9.0"
            },
            {
              "fixed": "1.9.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-54782"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-290",
      "CWE-347"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-06-19T20:47:11Z",
    "nvd_published_at": null,
    "severity": "CRITICAL"
  },
  "details": "### Impact\nFull impersonation of any principal the trusted STS could have issued an assertion for \u2014 including administrative principals when the relying party grants them via SAML claims. Affects both SAML 1.1 and SAML 2.0.\n\n#### Preconditions\nRelying-party service is hosted with WSFederationHttpBinding or WS2007FederationHttpBinding (or any binding that triggers FederatedSecurityTokenManager for issued-token validation), and IdentityConfiguration is wired (UseIdentityConfiguration = true).\nAttacker can reach the service over the network and knows the trusted STS\u2019s public certificate (public certs are by design discoverable).\n\n### Patches\nFixed in CoreWCF v1.8.1 and v1.9.1\n\n### Workarounds\nNone",
  "id": "GHSA-xjr9-gg9q-jx3v",
  "modified": "2026-06-19T20:47:11Z",
  "published": "2026-06-19T20:47:11Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/CoreWCF/CoreWCF/security/advisories/GHSA-xjr9-gg9q-jx3v"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/CoreWCF/CoreWCF"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "CoreWCF: Authentication bypass in CoreWCF SAML 1.1 / 2.0 token signature validation"
}

CVE-2026-54782 (GCVE-0-2026-54782)

Vulnerability from cvelistv5 – Published: 2026-07-08 22:20 – Updated: 2026-07-10 03:55

Title

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

Summary

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.

Severity

10 (Critical)


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

SSVC

Exploitation: none Automatable: yes Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-07-09 00:00 UTC

CWE

CWE-290 - Authentication Bypass by Spoofing
CWE-347 - Improper Verification of Cryptographic Signature

Assigner

GitHub_M CNA under the mitre root

CNA scorecard C 72/100 over 7566 records in the last 180 days details

References

6 references

URL	Tags
https://github.com/CoreWCF/CoreWCF/security/advis…	x_refsource_CONFIRM
https://github.com/CoreWCF/CoreWCF/commit/0b8c8af…	x_refsource_MISC
https://github.com/CoreWCF/CoreWCF/commit/0e63c2c…	x_refsource_MISC
https://github.com/CoreWCF/CoreWCF/commit/e5cc9b6…	x_refsource_MISC
https://github.com/CoreWCF/CoreWCF/releases/tag/v1.8.1	x_refsource_MISC
https://github.com/CoreWCF/CoreWCF/releases/tag/v1.9.1	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
CoreWCF	CoreWCF	Affected: >= 1.9.0, < 1.9.1 Affected: < 1.8.1

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-54782",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-07-09T00:00:00+00:00",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-07-10T03:55:37.656Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "CoreWCF",
          "vendor": "CoreWCF",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 1.9.0, \u003c 1.9.1"
            },
            {
              "status": "affected",
              "version": "\u003c 1.8.1"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "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."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 10,
            "baseSeverity": "CRITICAL",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "CHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-290",
              "description": "CWE-290: Authentication Bypass by Spoofing",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-347",
              "description": "CWE-347: Improper Verification of Cryptographic Signature",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-08T22:20:37.401Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/CoreWCF/CoreWCF/security/advisories/GHSA-xjr9-gg9q-jx3v",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/CoreWCF/CoreWCF/security/advisories/GHSA-xjr9-gg9q-jx3v"
        },
        {
          "name": "https://github.com/CoreWCF/CoreWCF/commit/0b8c8af851260e85e8402af53233d1b8f87dfb6f",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/CoreWCF/CoreWCF/commit/0b8c8af851260e85e8402af53233d1b8f87dfb6f"
        },
        {
          "name": "https://github.com/CoreWCF/CoreWCF/commit/0e63c2cca55763d8be6b226a234579280a09e7b6",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/CoreWCF/CoreWCF/commit/0e63c2cca55763d8be6b226a234579280a09e7b6"
        },
        {
          "name": "https://github.com/CoreWCF/CoreWCF/commit/e5cc9b6a4ecc102a50d782093bfc72e0790abe3d",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/CoreWCF/CoreWCF/commit/e5cc9b6a4ecc102a50d782093bfc72e0790abe3d"
        },
        {
          "name": "https://github.com/CoreWCF/CoreWCF/releases/tag/v1.8.1",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/CoreWCF/CoreWCF/releases/tag/v1.8.1"
        },
        {
          "name": "https://github.com/CoreWCF/CoreWCF/releases/tag/v1.9.1",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/CoreWCF/CoreWCF/releases/tag/v1.9.1"
        }
      ],
      "source": {
        "advisory": "GHSA-xjr9-gg9q-jx3v",
        "discovery": "UNKNOWN"
      },
      "title": "CoreWCF: Authentication bypass in CoreWCF SAML 1.1 / 2.0 token signature validation"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-54782",
    "datePublished": "2026-07-08T22:20:37.401Z",
    "dateReserved": "2026-06-15T23:23:57.714Z",
    "dateUpdated": "2026-07-10T03:55:37.656Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted