{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "9b9eb92e32a7a4b43b6d5108668941701c33e221"
            }
          ],
          "repo": "https://github.com/elysiajs/elysia-cors",
          "type": "GIT"
        }
      ]
    }
  ],
  "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.",
  "id": "CVE-2025-50864",
  "modified": "2026-04-01T23:08:35.064614214Z",
  "published": "2025-08-20T15:15:32.990Z",
  "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": "WEB",
      "url": "http://elysiajs.com"
    },
    {
      "type": "FIX",
      "url": "https://github.com/elysiajs/elysia-cors/commit/9b9eb92e32a7a4b43b6d5108668941701c33e221"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N",
      "type": "CVSS_V3"
    }
  ]
}