{"cve":"CVE-2025-66457","nvd":{"published":"2025-12-09T20:15:54.913","modified":"2026-10-14T21:10:00.183","status":"Analyzed","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_v4":{"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","score":7.5},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":8.8},"cwes":["CWE-94"],"references":["https://github.com/elysiajs/elysia/commit/26935bf76ebc43b4a43d48b173fc853de43bb51e","https://github.com/elysiajs/elysia/commit/3af978663e437dccc6c1a2a3aff4b74e1574849e","https://github.com/elysiajs/elysia/pull/1564","https://github.com/elysiajs/elysia/security/advisories/GHSA-8vch-m3f4-q8jf","https://github.com/elysiajs/elysia/security/advisories/GHSA-hxj9-33pp-j2cc"],"products":["elysiajs:elysia"],"source":"nvd","synced_at":"2026-10-19T22:16:40.427100871+00:00"},"epss":{"cve":"CVE-2025-66457","score":0.00807,"percentile":0.56539,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-8vch-m3f4-q8jf","url":"https://osv.dev/vulnerability/GHSA-8vch-m3f4-q8jf","summary":"Elysia affected by arbitrary code injection through cookie config","modified":"2026-02-04T03:09:32.992990Z","packages":[{"ecosystem":"npm","name":"elysia","purl":"pkg:npm/elysia","ranges":["<1.4.18"],"fixed":["1.4.18"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}