{"id":"CVE-2026-54774","aliases":["GHSA-rpj7-hr7h-w6p9"],"url":"https://o3.security/vulnerability/CVE-2026-54774","summary":"CoreWCF: SamlSerializer skips SignatureValue verification when SAML signing token is not an X.509 certificate","details":"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.","published":"2026-07-08T22:17:07.314Z","modified":"2026-08-12T03:51:18.238658645Z","cvss":{"score":7.4,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N"},"epss":{"score":0.0015,"percentile":0.04732,"asOf":"2026-08-21"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"NuGet","name":"CoreWCF.Primitives","fixedVersion":"1.8.1"},{"ecosystem":"NuGet","name":"CoreWCF.Primitives","fixedVersion":"1.9.1"}],"fix":{"url":"https://github.com/CoreWCF/CoreWCF/commit/65d09022749854ba943e376aefb958dec05b00d8","label":"CoreWCF/CoreWCF@65d0902"},"references":[{"type":"WEB","url":"https://github.com/CoreWCF/CoreWCF/releases/tag/v1.8.1"},{"type":"WEB","url":"https://github.com/CoreWCF/CoreWCF/releases/tag/v1.9.1"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/54xxx/CVE-2026-54774.json"},{"type":"ADVISORY","url":"https://github.com/CoreWCF/CoreWCF/security/advisories/GHSA-rpj7-hr7h-w6p9"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-54774"},{"type":"FIX","url":"https://github.com/CoreWCF/CoreWCF/commit/65d09022749854ba943e376aefb958dec05b00d8"},{"type":"FIX","url":"https://github.com/CoreWCF/CoreWCF/commit/b914495ce63c44924664643b60a262e7595081a4"},{"type":"FIX","url":"https://github.com/CoreWCF/CoreWCF/commit/e7454132876ecc7e2cf80e541a44376eeb54979b"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:18.238658645Z"}}