CVE-2025-66457
Versions 1.4.17 and below are subject to arbitrary code execution from cookie config.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.81%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 4.0
- 7.5 HIGHCVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.81% probability · 55th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-94
- Affected
- elysiajs/elysia
- Source
- security-advisories@github.com
References
- https://github.com/elysiajs/elysia/commit/26935bf76ebc43b4a43d48b173fc853de43bb51ePatch
- https://github.com/elysiajs/elysia/commit/3af978663e437dccc6c1a2a3aff4b74e1574849ePatch
- https://github.com/elysiajs/elysia/pull/1564Issue Tracking, Patch
- https://github.com/elysiajs/elysia/security/advisories/GHSA-8vch-m3f4-q8jfExploit, Patch, Vendor Advisory
- https://github.com/elysiajs/elysia/security/advisories/GHSA-hxj9-33pp-j2ccNot Applicable
- https://github.com/sportshead/elysia-pocExploit, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.