{"abstract":"Cors preflight header names are case insensitive.","category":"WebSocket and browser transport policies","checks":4,"contract":"Bounded offline decision model: cors preflight header names are case insensitive. Inputs are already validated protocol fields; the explicit fixtures define the supported policy, not a complete protocol implementation.","evaluation_group":"xh-cors-preflight-header-names-are-case-insensitive","failed_approach":"The attempted repair uses `bool(set(requested)&set(allowed))` and still violates a separate fixture.","family":"xh-cors-preflight-header-names-are-case-insensitive","id":"FA-7676","implementations":{"attempt":{"sha256":"c3bbf76907bf81d1c9a741e1d696786fcc2ddd4f9589324bbc8d5f960ab2652b","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport ipaddress\nimport re\nfrom urllib.parse import urlsplit, urljoin\nN = 1\nobservations = []\ndef solve(requested, allowed):\n    return bool(set(requested)&set(allowed))\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve(['X-Test'], ['x-test']), True)\", \"check('fixture 2', solve(['x', 'y'], ['x']), False)\", \"check('fixture 3', solve([], []), True)\", \"check('fixture 4', solve(['x'], []), False)\"]\nfor _line in _fixtures[N % len(_fixtures):] + _fixtures[:N % len(_fixtures)]:\n    exec(_line)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"},"broken":{"sha256":"5435fc6db663057dae9ab2d9611464da1d2630662749d6c323b3530b0efff3a6","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport ipaddress\nimport re\nfrom urllib.parse import urlsplit, urljoin\nN = 1\nobservations = []\ndef solve(requested, allowed):\n    return set(requested) <= set(allowed)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve(['X-Test'], ['x-test']), True)\", \"check('fixture 2', solve(['x', 'y'], ['x']), False)\", \"check('fixture 3', solve([], []), True)\", \"check('fixture 4', solve(['x'], []), False)\"]\nfor _line in _fixtures[N % len(_fixtures):] + _fixtures[:N % len(_fixtures)]:\n    exec(_line)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"},"fixed":{"sha256":"6d0d7f2ed5241aba49e8bbdf0afca084ca37fc384150f96da7889336e2879889","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport ipaddress\nimport re\nfrom urllib.parse import urlsplit, urljoin\nN = 1\nobservations = []\ndef solve(requested, allowed):\n    return {x.lower() for x in requested} <= {x.lower() for x in allowed}\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve(['X-Test'], ['x-test']), True)\", \"check('fixture 2', solve(['x', 'y'], ['x']), False)\", \"check('fixture 3', solve([], []), True)\", \"check('fixture 4', solve(['x'], []), False)\"]\nfor _line in _fixtures[N % len(_fixtures):] + _fixtures[:N % len(_fixtures)]:\n    exec(_line)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"}},"limitations":"Bounded deterministic policy model over validated inputs; not a complete protocol stack or an interoperability claim. The five variants rotate the same explicit fixture set. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.","method":"Deterministic executable model with adversarial boundary fixtures.","provenance":{"created_by":"Failure Map","dependencies":"Python standard library","family":"xh-cors-preflight-header-names-are-case-insensitive","generated_at":"2026-09-29T14:38:14.198337+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"This deterministic websocket and browser transport policies model isolates the cors-preflight-header-names-are-case-insensitive policy at a network component boundary.","repair":"Apply the explicit cors-preflight-header-names-are-case-insensitive contract, including the tested boundary and negative cases.","root_cause":"The faulty implementation uses `set(requested) <= set(allowed)` for the cors-preflight-header-names-are-case-insensitive decision.","sha256":"95bd17ce54a1a1b796002848eb579563302a9d643a0952ffb57fc3b3d48691cd","title":"Cors preflight header names are case insensitive · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":38.83,"exit_code":1,"observations":[{"actual":true,"check":"fixture 2","expected":false,"passed":false},{"actual":false,"check":"fixture 3","expected":true,"passed":false},{"actual":false,"check":"fixture 4","expected":false,"passed":true},{"actual":false,"check":"fixture 1","expected":true,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": true, \"expected\": false, \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": false, \"expected\": true, \"passed\": false}, {\"check\": \"fixture 4\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"fixture 1\", \"actual\": false, \"expected\": true, \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":38.889,"exit_code":1,"observations":[{"actual":false,"check":"fixture 2","expected":false,"passed":true},{"actual":true,"check":"fixture 3","expected":true,"passed":true},{"actual":false,"check":"fixture 4","expected":false,"passed":true},{"actual":false,"check":"fixture 1","expected":true,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"fixture 1\", \"actual\": false, \"expected\": true, \"passed\": false}], \"passed\": false}\n"},"fixed":{"elapsed_ms":38.216,"exit_code":0,"observations":[{"actual":false,"check":"fixture 2","expected":false,"passed":true},{"actual":true,"check":"fixture 3","expected":true,"passed":true},{"actual":false,"check":"fixture 4","expected":false,"passed":true},{"actual":true,"check":"fixture 1","expected":true,"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"fixture 1\", \"actual\": true, \"expected\": true, \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}