Elysia is a Typescript framework for request validation, type inference, OpenAPI documentation and client-server communication. Versions 1.4.17 and below are subject to arbitrary code execution from cookie config. When dynamic cookies are enabled (e.g. there an existing cookie schema), the cookie config is injected into the compiled route without first being sanitised. Availability of this exploit is generally low, but when combined with GHSA-hxj9-33pp-j2cc, it allows for a full RCE chain. An attack requires write access to either the Elysia app's source code (in which case the vulnerability is meaningless) or write access to the cookie config (perhaps where it is assumed to be provisioned by the environment). This issue is fixed in version 1.4.18.
Advisories
Source ID Title
Github GHSA Github GHSA GHSA-8vch-m3f4-q8jf Elysia affected by arbitrary code injection through cookie config
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Wed, 10 Dec 2025 21:45:00 +0000

Type Values Removed Values Added
First Time appeared Elysiajs
Elysiajs elysia
Vendors & Products Elysiajs
Elysiajs elysia

Tue, 09 Dec 2025 20:15:00 +0000

Type Values Removed Values Added
Description Elysia is a Typescript framework for request validation, type inference, OpenAPI documentation and client-server communication. Versions 1.4.17 and below are subject to arbitrary code execution from cookie config. When dynamic cookies are enabled (e.g. there an existing cookie schema), the cookie config is injected into the compiled route without first being sanitised. Availability of this exploit is generally low, but when combined with GHSA-hxj9-33pp-j2cc, it allows for a full RCE chain. An attack requires write access to either the Elysia app's source code (in which case the vulnerability is meaningless) or write access to the cookie config (perhaps where it is assumed to be provisioned by the environment). This issue is fixed in version 1.4.18.
Title Elysia affected by arbitrary code injection through cookie config
Weaknesses CWE-94
References
Metrics cvssV4_0

{'score': 7.5, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2025-12-09T20:03:45.918Z

Reserved: 2025-12-01T22:51:54.581Z

Link: CVE-2025-66457

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2025-12-09T20:15:54.913

Modified: 2025-12-12T15:19:07.567

Link: CVE-2025-66457

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2025-12-10T21:33:21Z

Weaknesses