{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "better-call"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.0.12"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [],
  "database_specific": {
    "cwe_ids": [
      "CWE-525"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2025-07-11T17:09:53Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "### Summary\n\nUsing a CDN that caches (`/**/*.png`, `/**/*.json`, `/**/*.css`, etc...) requests, a cache deception can emerge. This could lead to unauthorized access to user sessions and personal data when cached responses are served to other users.\n\n### Details\n\nThe vulnerability occurs in the request processing logic where path sanitization is insufficient. The library splits the path using `config.basePath` but doesn\u0027t properly validate the remaining path components. This allows specially crafted requests that appear to be static assets (like `/api/auth/get-session/api/auth/image.png` assuming `config.basePath`=`/api/auth`) to bypass typical CDN cache exclusion rules while actually returning sensitive data.\n\nThe problematic code [here](https://github.com/Bekacru/better-call/blob/8b6f13e24fad7f4666a582601517bb3232d4f4af/src/router.ts#L124):\n```js\n\tconst processRequest = async (request: Request) =\u003e {\n\t\tconst url = new URL(request.url);\n\t\tconst path = config?.basePath ? url.pathname.split(config.basePath)[1] : url.pathname;\n```\n\nSince this library is largely coupled with `better-auth`, it becomes more clear why this can be dangerous with an example request:\n\n\u003cimg width=\"800\" alt=\"image\" src=\"https://github.com/user-attachments/assets/2ab7c4dd-0700-4f59-863f-79f2b5edbb37\" /\u003e\n\n### Impact\n\nThis is a cache deception vulnerability affecting `better-call` users with CDN caching enabled. which can expose sensitive data.",
  "id": "GHSA-hq75-xg7r-rx6c",
  "modified": "2025-07-11T17:09:53Z",
  "published": "2025-07-11T17:09:53Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/Bekacru/better-call/security/advisories/GHSA-hq75-xg7r-rx6c"
    },
    {
      "type": "WEB",
      "url": "https://github.com/Bekacru/better-call/commit/7c7d31b"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/Bekacru/better-call"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Better Call routing bug can lead to Cache Deception"
}