{"id":"CVE-2026-48819","revision":"3e345cb263034a269a24862056578188","records":[{"revision":"3e345cb263034a269a24862056578188","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-48819","aliases":[],"title":"Hey API: `buildClientParams` template: prototype chain substitution via unknown `$<slot>___proto__` key","description":"Hey API is an ecosystem for turning API specifications into production-ready code. Prior to 0.97.3, dist/clients/core/params.ts ships a runtime template copied into generated SDKs as params.gen.ts, and buildClientParams writes unknown slot-prefixed keys such as $body_, $headers_, $path_, and $query_ directly to the corresponding slot, allowing $query___proto__ alongside a legitimate q field to set params.query through params[\"query\"][\"__proto__\"] = value, call Object.setPrototypeOf(params.query, value), and expose inherited attacker-controlled keys during for..in iteration. This issue is fixed in version 0.97.3.","state":0,"publishedAt":"2026-07-17T19:46:00.402+00:00","modifiedAt":"2026-07-20T16:24:20.624+00:00","affected":[{"ecosystem":"Vendor product","name":"openapi-ts","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"hey-api\",\n                    \"product\": \"openapi-ts\",\n                    \"versions\": [\n                        {\n                            \"version\": \"< 0.97.3\",\n                            \"status\": \"affected\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N","score":4.8,"severity":"MEDIUM"}],"references":["https://github.com/hey-api/hey-api/security/advisories/GHSA-hhx9-57xq-r5rw","https://github.com/hey-api/hey-api/commit/023909137a15eff9c0263d3bcd116140076b214f","https://github.com/hey-api/hey-api/commit/da321a1529eb3c90d2109da870f514b915a60169","https://github.com/hey-api/hey-api/releases/tag/%40hey-api%2Fopenapi-ts%400.97.3"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-48819","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-48819","identifiers":["CVE-2026-48819"]},"retained":false,"historicalAffected":[]}],"coverage":[]}