{"id":"CVE-2026-54774","aliases":["EUVD-2026-42470","GHSA-rpj7-hr7h-w6p9"],"status":"published","title":"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.","severity":{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00203,"percentile":0.1036,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-345","CWE-347"],"published":"2026-06-19T20:46:46Z","modified":"2026-10-28T02:30:21Z","fixes":[{"ecosystem":"NuGet","package":"CoreWCF.Primitives","fixed_in":["1.8.1","1.9.1"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"NuGet","package":"CoreWCF.Primitives","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.8.1"}]}]},{"source":"ghsa","ecosystem":"NuGet","package":"CoreWCF.Primitives","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"1.9.0"},{"fixed":"1.9.1"}]}]},{"source":"osv","ecosystem":"NuGet","package":"CoreWCF.Primitives","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.8.1"}]}],"versions":["0.1.0","0.1.0-preview","0.1.0-preview-2","0.2.0","0.2.1","0.3.0","0.3.1","0.3.2","0.4.0","1.0.0","1.0.0-preview1","1.0.0-preview2","1.0.1","1.0.2","1.1.0","1.1.1","1.2.0","1.2.1","1.3.0","1.3.1","1.3.2","1.4.0","1.4.0-preview1","1.4.1","1.4.2","1.5.0","1.5.0-preview1","1.5.1","1.5.2","1.6.0","1.7.0","1.8.0"]},{"source":"osv","ecosystem":"NuGet","package":"CoreWCF.Primitives","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"1.9.0"},{"fixed":"1.9.1"}]}],"versions":["1.9.0"]}],"products":[{"vendor":"corewcf","product":"corewcf"}],"references":[{"url":"https://github.com/CoreWCF/CoreWCF/security/advisories/GHSA-rpj7-hr7h-w6p9","tags":["x_refsource_CONFIRM","advisory","web"]},{"url":"https://github.com/CoreWCF/CoreWCF/commit/65d09022749854ba943e376aefb958dec05b00d8","tags":["x_refsource_MISC","fix"]},{"url":"https://github.com/CoreWCF/CoreWCF/commit/b914495ce63c44924664643b60a262e7595081a4","tags":["x_refsource_MISC","fix"]},{"url":"https://github.com/CoreWCF/CoreWCF/commit/e7454132876ecc7e2cf80e541a44376eeb54979b","tags":["x_refsource_MISC","fix"]},{"url":"https://github.com/CoreWCF/CoreWCF/releases/tag/v1.8.1","tags":["x_refsource_MISC","web"]},{"url":"https://github.com/CoreWCF/CoreWCF/releases/tag/v1.9.1","tags":["x_refsource_MISC","web"]},{"url":"https://github.com/advisories/GHSA-rpj7-hr7h-w6p9"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/54xxx/CVE-2026-54774.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-54774","tags":["advisory"]},{"url":"https://github.com/CoreWCF/CoreWCF","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-54774","title":"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.","status":"published","published":"2026-07-08T22:17:07.314Z","modified":"2026-07-10T03:55:39.135Z","cvss":[{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"high","assessor":"cna"}],"cwes":["CWE-345","CWE-347"],"updated_at":"2026-11-02T13:37:58.613221Z"}],"euvd":[{"id":"EUVD-2026-42470","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.","status":"published","published":"2026-07-08T22:17:07Z","modified":"2026-07-10T03:55:39Z","cvss":[{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"high"}],"updated_at":"2026-11-02T18:20:03.742277Z"}],"ghsa":[{"id":"GHSA-rpj7-hr7h-w6p9","title":"CoreWCF: SamlSerializer skips SignatureValue verification when SAML signing token is not an X.509 certificate","description":"### Impact\nWhen a service is configured to validate SAML tokens using a method other than X.509 certificate signing, the final signature verification is skipped.\n\n#### Preconditions\nThe service is configured to authenticate using SAML tokens and an out of band token resolver (commonly the IssuerTokenResolver of IssuedTokenServiceCredential) holds a non-X.509 SecurityToken whose key identifier the attacker can reference in the assertion’s `\u003cKeyInfo\u003e` - for example a `BinarySecretSecurityToken` representing the symmetric proof key issued by a WS-Trust symmetric-key holder-of-key STS.\n\n### Patches\nFixed in CoreWCF v1.8.1 and v1.9.1\n\n### Workarounds\nNone","status":"published","published":"2026-06-19T20:46:46Z","modified":"2026-06-19T20:46:48Z","cvss":[{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"high"}],"cwes":["CWE-345","CWE-347"],"updated_at":"2026-11-02T14:40:31.656952Z"}],"nvd":[{"id":"CVE-2026-54774","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.","status":"published","published":"2026-07-08T23:16:55.09Z","modified":"2026-07-10T05:16:37.267Z","cvss":[{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"high","assessor":"secondary"}],"cwes":["CWE-345","CWE-347"],"updated_at":"2026-11-02T14:12:28.4135Z"}],"osv":[{"id":"CVE-2026-54774","title":"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.","status":"published","published":"2026-07-08T22:17:07.314Z","modified":"2026-10-28T02:30:21.377772221Z","cvss":[{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"high"}],"cwes":["CWE-345","CWE-347"],"updated_at":"2026-11-02T15:45:10.818486Z"},{"id":"GHSA-rpj7-hr7h-w6p9","title":"CoreWCF: SamlSerializer skips SignatureValue verification when SAML signing token is not an X.509 certificate","description":"### Impact\nWhen a service is configured to validate SAML tokens using a method other than X.509 certificate signing, the final signature verification is skipped.\n\n#### Preconditions\nThe service is configured to authenticate using SAML tokens and an out of band token resolver (commonly the IssuerTokenResolver of IssuedTokenServiceCredential) holds a non-X.509 SecurityToken whose key identifier the attacker can reference in the assertion’s `\u003cKeyInfo\u003e` - for example a `BinarySecretSecurityToken` representing the symmetric proof key issued by a WS-Trust symmetric-key holder-of-key STS.\n\n### Patches\nFixed in CoreWCF v1.8.1 and v1.9.1\n\n### Workarounds\nNone","status":"published","published":"2026-06-19T20:46:46Z","modified":"2026-06-19T21:11:30.138754Z","cvss":[{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"high"}],"cwes":["CWE-345","CWE-347"],"updated_at":"2026-11-02T15:46:56.281047Z"}]}}