Prototype Pollution in Hey-api Openapi-ts

CVE-2026-48819

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…

Vulnerability class: Prototype Pollution

CVSS v3 metric

CVSS v3 base score 4.8 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-48819?
CVE-2026-48819 is a medium-severity vulnerability in Hey-api Openapi-ts, classified under Improperly Controlled Modification of Object Prototype Attributes (Prototype Pollution). CVSS score: 4.8/10. Published 2026-07-17.
How severe is CVE-2026-48819?
Medium severity. CVSS v3 base score is 4.8 out of 10.