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MCP 2026-07-28 describes increased-scope reauthorisation after insufficient_scope, rather than treating token renewal as new authority. A refreshed token can renew existing access; possession or successful refresh alone does not establish a grant for newly challenged scopes.", "related_record_ids": [], "source_review": { "source_type": "official_external_documentation", "source_title": "RFC 6749: OAuth 2.0, section 6 refresh scope", "source_url": "https://www.rfc-editor.org/rfc/rfc6749.txt", "checked_on": "2026-10-31", "candidate_record_id": "VXI-EXT-ICE12-MCP-REFRESH-TOKEN-SCOPE-EXPANSION-BOUNDARY-01-v1", "candidate_record_sha256": "0a37c808a3ad3c8371ee0147c792cb4df708eef82fe2ab0116976b6fb0a2d68d", "method": "Primary documentation reviewed for the published bounded statement.", "deployment_tested_by_varexis": false, "revalidation": "The delivered snapshot preserves the review date shown. 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Full source capture remains private; no source code, examples or vendor documentation is redistributed. Anthropic repository MIT licensing and IETF source notices remain with original sources.", "reviewed_sections": [ "Refreshing an Access Token" ] }, { "source_id": "mcp-auth", "url": "https://modelcontextprotocol.io/specification/2026-07-28/basic/authorization.md", "final_url": "https://modelcontextprotocol.io/specification/2026-07-28/basic/authorization.md", "captured_at_utc": "2026-10-31T14:07:23.008429+00:00", "status": 200, "content_type": "text/markdown; charset=utf-8", "bytes": 25510, "sha256": "59bc8d07ef88538e4d4e539ca1c846c3ae3162e7911dc29453495cddeac18444", "title": "MCP HTTP authorization, specification 2026-07-28", "publisher": "Model Context Protocol", "checked_on": "2026-10-31", "capture_status": "captured_primary_documentation", "claim_review_completed": true, "hash_basis": "Raw HTTP response bytes retained privately; not deployment attestation.", "version_context": "MCP specification 2026-07-28", "rights_disposition": "Original bounded paraphrase with source attribution. Full source capture remains private; no source code, examples or vendor documentation is redistributed. Anthropic repository MIT licensing and IETF source notices remain with original sources.", "reviewed_sections": [ "Step-Up Authorization Flow", "previously requested scope set", "Retry the original request", "same resource and operation" ] } ], "observed_deployment": false, "commercial_reliance_boundary": "Documentation supports only the stated boundary. Existing licensed checkers analyse supported supplied declarations locally; they do not inspect provider accounts, verify live behaviour, enforce decisions or certify compliance.", "paid_value": { "decision_context": "Refuse additional-authority approval from refresh success alone. Distinguish expiry from insufficient scope, verify the existing grant and perform the applicable reauthorisation flow or stop. 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