{"cve":"CVE-2025-50864","nvd":{"published":"2025-08-20T15:15:32.990","modified":"2026-07-05T02:16:51.173","status":"Deferred","description":"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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N","score":6.5},"cwes":["CWE-178"],"references":["https://github.com/elysiajs/elysia-cors/blob/main/src/index.ts","https://github.com/elysiajs/elysia-cors/commit/9b9eb92e32a7a4b43b6d5108668941701c33e221","https://github.com/elysiajs/elysia-cors/tree/main","https://medium.com/@raghavagrawal_23036/cors-bypass-in-popular-opensource-library-ad27fb41e16a"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:07:46.309729541+00:00"},"epss":{"cve":"CVE-2025-50864","score":0.00493,"percentile":0.42361,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-f9qj-4c5x-cpcw","url":"https://osv.dev/vulnerability/GHSA-f9qj-4c5x-cpcw","summary":"elysia-cors Origin Validation Error","modified":"2026-02-03T03:05:27.058127Z","packages":[{"ecosystem":"npm","name":"@elysiajs/cors","purl":"pkg:npm/%40elysiajs/cors","ranges":["<1.3.1"],"fixed":["1.3.1"]}]}],"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."]}