{"id":"GHSA-2288-8h3r-cqgg","summary":"CoreWCF: SPNEGO SecurityContextToken proof key wrapped without confidentiality","details":"### Impact\nWhen the proof key recovered from the RSTR can be observed by a party that is not the legitimate client, that party can impersonate the authenticated Windows principal for the lifetime of the SCT (default ~10 hours) and decrypt or forge any subsequent WS‑SecureConversation traffic that uses keys derived from the SCT.\n\n#### Preconditions\nUsing security mode TransportWithMessageCredential with client credential type Windows, along with session establishment (which triggers use of WS-SecureConversation).\n\n### Patches\nFixed in CoreWCF v1.9.1\n\n### Workarounds\nEnsure communication is protected by SSL/TLS to prevent capturing of SCT negotiation handshake.","aliases":["CVE-2026-54784"],"modified":"2026-06-19T21:11:29.162057Z","published":"2026-06-19T20:47:17Z","database_specific":{"github_reviewed_at":"2026-06-19T20:47:17Z","nvd_published_at":null,"cwe_ids":["CWE-311","CWE-523"],"severity":"HIGH","github_reviewed":true},"references":[{"type":"WEB","url":"https://github.com/CoreWCF/CoreWCF/security/advisories/GHSA-2288-8h3r-cqgg"},{"type":"PACKAGE","url":"https://github.com/CoreWCF/CoreWCF"}],"affected":[{"package":{"name":"CoreWCF.Primitives","ecosystem":"NuGet","purl":"pkg:nuget/CoreWCF.Primitives"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"1.9.0"},{"fixed":"1.9.1"}]}],"versions":["1.9.0"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-2288-8h3r-cqgg/GHSA-2288-8h3r-cqgg.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N"}]}