{"id":"CVE-2026-54781","state":"PUBLISHED","title":"CoreWCF: SAML SubjectConfirmation methods and holder-of-key proof keys are not enforced","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 token validation does not enforce SubjectConfirmation method URIs or holder-of-key proof keys in SamlSecurityTokenHandler, allowing holder-of-key downgrade or custom confirmation method assertions to authenticate a subject without proving authority over the assertion. This issue is fixed in versions 1.8.1 and 1.9.1.","publishedAt":"2026-07-08T22:19:40.784Z","updatedAt":"2026-07-09T14:40:11.234Z","severity":{"score":7.4,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["CoreWCF CoreWCF"],"affected":[{"vendor":"CoreWCF","product":"CoreWCF","versions":[{"version":">= 1.9.0, < 1.9.1","status":"affected"},{"version":"< 1.8.1","status":"affected"}]}],"references":["https://github.com/CoreWCF/CoreWCF/security/advisories/GHSA-48pq-2xq3-c2m4","https://github.com/CoreWCF/CoreWCF/commit/6a99df3242f54acd6f89edfd6050430b72d0c685","https://github.com/CoreWCF/CoreWCF/commit/86dd3232b6b8aaf32281be9e8d798afad6145d58","https://github.com/CoreWCF/CoreWCF/commit/9eb9b46d1c2af06fb71f656a02f4d5b4649c1f03","https://github.com/CoreWCF/CoreWCF/releases/tag/v1.8.1","https://github.com/CoreWCF/CoreWCF/releases/tag/v1.9.1"],"weaknesses":["CWE-287","CWE-345"],"ingestedAt":"2026-10-29T20:12:24.861Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/54xxx/CVE-2026-54781.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-54781","state":"PUBLISHED","datePublished":"2026-07-08T22:19:40.784Z","dateUpdated":"2026-07-09T14:40:11.234Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-06-15T23:23:57.714Z"},"containers":{"cna":{"title":"CoreWCF: SAML SubjectConfirmation methods and holder-of-key proof keys are not enforced","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 token validation does not enforce SubjectConfirmation method URIs or holder-of-key proof keys in SamlSecurityTokenHandler, allowing holder-of-key downgrade or custom confirmation method assertions to authenticate a subject without proving authority over the assertion. This issue is fixed in versions 1.8.1 and 1.9.1."}],"affected":[{"vendor":"CoreWCF","product":"CoreWCF","versions":[{"version":">= 1.9.0, < 1.9.1","status":"affected"},{"version":"< 1.8.1","status":"affected"}]}],"references":[{"url":"https://github.com/CoreWCF/CoreWCF/security/advisories/GHSA-48pq-2xq3-c2m4","name":"https://github.com/CoreWCF/CoreWCF/security/advisories/GHSA-48pq-2xq3-c2m4","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/CoreWCF/CoreWCF/commit/6a99df3242f54acd6f89edfd6050430b72d0c685","name":"https://github.com/CoreWCF/CoreWCF/commit/6a99df3242f54acd6f89edfd6050430b72d0c685","tags":["x_refsource_MISC"]},{"url":"https://github.com/CoreWCF/CoreWCF/commit/86dd3232b6b8aaf32281be9e8d798afad6145d58","name":"https://github.com/CoreWCF/CoreWCF/commit/86dd3232b6b8aaf32281be9e8d798afad6145d58","tags":["x_refsource_MISC"]},{"url":"https://github.com/CoreWCF/CoreWCF/commit/9eb9b46d1c2af06fb71f656a02f4d5b4649c1f03","name":"https://github.com/CoreWCF/CoreWCF/commit/9eb9b46d1c2af06fb71f656a02f4d5b4649c1f03","tags":["x_refsource_MISC"]},{"url":"https://github.com/CoreWCF/CoreWCF/releases/tag/v1.8.1","name":"https://github.com/CoreWCF/CoreWCF/releases/tag/v1.8.1","tags":["x_refsource_MISC"]},{"url":"https://github.com/CoreWCF/CoreWCF/releases/tag/v1.9.1","name":"https://github.com/CoreWCF/CoreWCF/releases/tag/v1.9.1","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":7.4,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-287","lang":"en","description":"CWE-287: Improper Authentication","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-345","lang":"en","description":"CWE-345: Insufficient Verification of Data Authenticity","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-07-08T22:19:40.784Z"},"source":{"advisory":"GHSA-48pq-2xq3-c2m4","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-07-09T14:31:13.261626Z","id":"CVE-2026-54781","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-07-09T14:40:11.234Z"}}]}}}