{"id":"CVE-2026-54773","aliases":["GHSA-jc6x-rj79-w4mx"],"url":"https://o3.security/vulnerability/CVE-2026-54773","summary":"CoreWCF: WS-Security signature substitution via document-wide Signature lookup","details":"### Impact\nAn unauthenticated remote attacker who can place a SOAP header lexically before `wsse:Security` can embed a `ds:Signature` of their choosing inside that header and cause the server to verify the attacker-supplied signature instead of the one carried in the security header.\n\n#### Preconditions\nExploitation requires the endpoint be configured with an endorsing supporting token binding, and the attacker constructs a `ds:Signature` whose `KeyInfo` resolves through the receive-side token resolver to a key under the attacker’s control. Both are conditions outside the attacker’s direct control on a generic deployment.\n\n### Patches\nFixed in CoreWCF v1.8.1 and v1.9.1\n\n### Workarounds\nUse a security token resolver that only accepts references to issuer-pinned X.509 chains (the default when expecting a static set of signing certificates).","published":"2026-07-08T22:09:32.584Z","modified":"2026-10-28T02:30:51.737653576Z","cvss":{"score":5.9,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N"},"epss":{"score":0.0037,"percentile":0.30645,"asOf":"2026-09-17"},"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/0589692d4b9a41d21b34ac48281e95f6df7f4ce5","label":"CoreWCF/CoreWCF@0589692"},"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-2026-54773.json"},{"type":"ADVISORY","url":"https://github.com/CoreWCF/CoreWCF/security/advisories/GHSA-jc6x-rj79-w4mx"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-54773"},{"type":"FIX","url":"https://github.com/CoreWCF/CoreWCF/commit/0589692d4b9a41d21b34ac48281e95f6df7f4ce5"},{"type":"FIX","url":"https://github.com/CoreWCF/CoreWCF/commit/30aef805270976c42477e3f2a05f4e563d86e247"},{"type":"FIX","url":"https://github.com/CoreWCF/CoreWCF/commit/4618f24165ad018ad3ed2636bf8c3bc87d2a3be2"},{"type":"PACKAGE","url":"https://github.com/CoreWCF/CoreWCF"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-10-28T02:30:51.737653576Z"}}