{"id":"CVE-2025-50864","aliases":["GHSA-f9qj-4c5x-cpcw"],"url":"https://o3.security/vulnerability/CVE-2025-50864","summary":"elysia-cors Origin Validation Error","details":"An Origin Validation Error in the elysia-cors library thru 1.3.0 allows attackers to bypass Cross-Origin Resource Sharing (CORS) restrictions. The library incorrectly validates the supplied origin by checking if it is a substring of any domain in the site's CORS policy, rather than performing an exact match. For example, a malicious origin like \"notexample.com\", \"example.common.net\" is whitelisted when the site's CORS policy specifies \"example.com.\" This vulnerability enables unauthorized access to user data on sites using the elysia-cors library for CORS validation.","published":"2025-08-20T00:00:00Z","modified":"2026-07-15T01:49:17.425903658Z","cvss":{"score":6.5,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"@elysiajs/cors","fixedVersion":"1.3.1"}],"fix":{"url":"https://github.com/elysiajs/elysia-cors/commit/9b9eb92e32a7a4b43b6d5108668941701c33e221","label":"elysiajs/elysia-cors@9b9eb92"},"references":[{"type":"WEB","url":"https://github.com/elysiajs/elysia-cors/blob/main/src/index.ts"},{"type":"WEB","url":"https://github.com/elysiajs/elysia-cors/tree/main"},{"type":"WEB","url":"https://medium.com/@raghavagrawal_23036/cors-bypass-in-popular-opensource-library-ad27fb41e16a"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/50xxx/CVE-2025-50864.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-50864"},{"type":"FIX","url":"https://github.com/elysiajs/elysia-cors/commit/9b9eb92e32a7a4b43b6d5108668941701c33e221"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-15T01:49:17.425903658Z"}}