CVE-2025-66457

Elysia affected by arbitrary code injection through cookie config

Published Dec 9, 2025 CVSS 4.0 · 7.5 High EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-8vch-m3f4-q8jf Elysia affected by arbitrary code injection through cookie config
History
Type Values Removed Values Added
CPEs cpe:2.3:a:elysiajs:elysia:*:*:*:*:*:node.js:*:*
Metrics cvssV3_1

{'score': 8.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}

Type Values Removed Values Added
References
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}

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

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Dec 12, 2025, 7:39 PM
Reserved
Dec 1, 2025, 10:51 PM
Status
Analyzed
Published
Dec 9, 2025, 8:15 PM
Modified
Oct 14, 2026, 9:10 PM