CVE-2026-31865 — Elysia Cookie Value Prototype Pollution
Elysia is a Typescript framework for request validation, type inference, OpenAPI documentation, and client-server communication. Prior to version 1.4.27, an Elysia cookie can be…
Published: 2026-03-18 · CVSS: 6.5 · CVSS 3.1
Elysia is a Typescript framework for request validation, type inference, OpenAPI documentation, and client-server communication. Prior to version 1.4.27, an Elysia cookie can be overridden by prototype pollution , eg. `__proto__`. This issue is patched in 1.4.27. As a workaround, use t.Cookie validation to enforce validation value and/or prevent iterable over cookie if possible.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7