CVE-2026-48819
CVE-2026-48819 · Hey API: `buildClientParams` template: prototype chain substitution via unknown `$<slot>___proto__` key
This page contains facts from public vulnerability sources. Check the original advisory before updating.
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.
CVSS 4.8 · Medium · EPSS 0.3% · Fix available
- Published
- Updated
Stack: node
Affected products and versions
openapi-ts
- Versions
- < 0.97.3: Affected
No fix published
@hey-api/openapi-ts npm
- Affected ranges
- SEMVER: < 0.97.3
Update to 0.97.3
Original sources
- 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
- https://nvd.nist.gov/vuln/detail/CVE-2026-48819