{"abstract":"Cors preflight method matching is case sensitive.","category":"WebSocket and browser transport policies","checks":4,"contract":"Given method, allowed, credentialed, cors preflight method matching is case sensitive. Return the protocol decision or transformed value; fields are validated and fixtures state boundary outcomes.","evaluation_group":"xh-cors-preflight-method-matching-is-case-sensitive","failed_approach":"The attempted repair uses `method in allowed` and still violates a separate fixture.","family":"xh-cors-preflight-method-matching-is-case-sensitive","id":"FA-7671","implementations":{"attempt":{"sha256":"aedf56a43be2e029ab1d6a43869bf5cc29eb42a6193771dc43501138f208ec63","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(method, allowed, credentialed):\n    return method 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('get', ['GET'], False), False)\", \"check('fixture 2', solve('PUT', ['*'], False), True)\", \"check('fixture 3', solve('PUT', ['*'], True), False)\", \"check('fixture 4', solve('GET', ['GET'], True), True)\"]\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":"9b20717afcbffbd6764327c83da5d7f35d1f4341e6a69e96bb98cf7fda52a593","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(method, allowed, credentialed):\n    return method.upper() in {a.upper() for a in allowed} or \"*\" 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('get', ['GET'], False), False)\", \"check('fixture 2', solve('PUT', ['*'], False), True)\", \"check('fixture 3', solve('PUT', ['*'], True), False)\", \"check('fixture 4', solve('GET', ['GET'], True), True)\"]\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":"1dce64648c0b20183b9f1c02fcee4b9c992a69ec505b00e44715a4a8853cc90c","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(method, allowed, credentialed):\n    return method in allowed or (\"*\" in allowed and not credentialed)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve('get', ['GET'], False), False)\", \"check('fixture 2', solve('PUT', ['*'], False), True)\", \"check('fixture 3', solve('PUT', ['*'], True), False)\", \"check('fixture 4', solve('GET', ['GET'], True), True)\"]\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-method-matching-is-case-sensitive","generated_at":"2026-09-29T14:38:14.177592+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-method-matching-is-case-sensitive policy at a network component boundary.","repair":"Apply the explicit cors-preflight-method-matching-is-case-sensitive contract, including the tested boundary and negative cases.","root_cause":"The faulty implementation uses `method.upper() in {a.upper() for a in allowed} or \"*\" in allowed` for the cors-preflight-method-matching-is-case-sensitive decision.","sha256":"fc6077c8395dd837a98f8ee36227375bf289b2d2c10517f7926428828a34fcb8","title":"Cors preflight method matching is case sensitive · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":38.855,"exit_code":1,"observations":[{"actual":false,"check":"fixture 2","expected":true,"passed":false},{"actual":false,"check":"fixture 3","expected":false,"passed":true},{"actual":true,"check":"fixture 4","expected":true,"passed":true},{"actual":false,"check":"fixture 1","expected":false,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": false, \"expected\": true, \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"fixture 1\", \"actual\": false, \"expected\": false, \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":38.83,"exit_code":1,"observations":[{"actual":true,"check":"fixture 2","expected":true,"passed":true},{"actual":true,"check":"fixture 3","expected":false,"passed":false},{"actual":true,"check":"fixture 4","expected":true,"passed":true},{"actual":true,"check":"fixture 1","expected":false,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": true, \"expected\": false, \"passed\": false}, {\"check\": \"fixture 4\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"fixture 1\", \"actual\": true, \"expected\": false, \"passed\": false}], \"passed\": false}\n"},"fixed":{"elapsed_ms":39.444,"exit_code":0,"observations":[{"actual":true,"check":"fixture 2","expected":true,"passed":true},{"actual":false,"check":"fixture 3","expected":false,"passed":true},{"actual":true,"check":"fixture 4","expected":true,"passed":true},{"actual":false,"check":"fixture 1","expected":false,"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"fixture 1\", \"actual\": false, \"expected\": false, \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}