Hey API: `buildClientParams` template: prototype chain substitution via unknown `$<slot>___proto__` key
Summary
| CVE | CVE-2026-48819 |
|---|---|
| State | PUBLISHED |
| Assigner | GitHub_M |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-07-17 20:17:21 UTC |
| Updated | 2026-07-17 20:17:21 UTC |
| 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. |
Risk And Classification
Primary CVSS: v3.1 4.8 MEDIUM from [email protected]
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
Problem Types: CWE-1321 | CWE-1321 CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 4.8 | MEDIUM | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N |
| 3.1 | CNA | DECLARED | 4.8 | MEDIUM | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
HighPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
LowIntegrity
LowAvailability
NoneCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Hey-api | Openapi-ts | affected < 0.97.3 | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/hey-api/hey-api/releases/tag/%40hey-api%2Fopenapi-ts%400.97.3 | [email protected] | github.com | |
| github.com/hey-api/hey-api/commit/023909137a15eff9c0263d3bcd116140076b214f | [email protected] | github.com | |
| github.com/hey-api/hey-api/commit/da321a1529eb3c90d2109da870f514b915a60169 | [email protected] | github.com | |
| github.com/hey-api/hey-api/security/advisories/GHSA-hhx9-57xq-r5rw | [email protected] | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.