{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "1.4.8-beta.7"
              },
              {
                "fixed": "1.6.0"
              },
              {
                "introduced": "1.6.0"
              },
              {
                "fixed": "1.6.11"
              }
            ],
            "source": "AFFECTED_FIELD"
          },
          "events": [
            {
              "introduced": "9d784407ca40224c9072a71ad88550f1b1353bf8"
            },
            {
              "fixed": "0e3f188020fa785d44d0019a3a3c8407a4cc8d5f"
            },
            {
              "introduced": "0e3f188020fa785d44d0019a3a3c8407a4cc8d5f"
            },
            {
              "fixed": "f41514ef07cfafc5dbf463bd1500aee6575d88a7"
            }
          ],
          "repo": "https://github.com/better-auth/better-auth",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-392p-2q2v-4372"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-362",
      "CWE-367"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53517.json"
  },
  "details": "Better Auth is an authentication and authorization library for TypeScript. From 1.4.8-beta.7 until 1.6.11, the @better-auth/oauth-provider POST /oauth2/token endpoint on the refresh_token grant performs a non-atomic read, validate, revoke, and mint sequence on the oauthRefreshToken row, allowing concurrent requests with the same parent refresh token to pass the revoked check and create forked refresh-token families; the vulnerable range also includes embedded better-auth plugin versions before 1.6.0. This issue is fixed in version 1.6.11.",
  "id": "CVE-2026-53517",
  "modified": "2026-07-17T03:41:54.569857239Z",
  "published": "2026-07-15T17:33:38.943Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/better-auth/better-auth/releases/tag/v1.6.11"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53517.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/better-auth/better-auth/security/advisories/GHSA-392p-2q2v-4372"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-53517"
    },
    {
      "type": "FIX",
      "url": "https://github.com/better-auth/better-auth/commit/c6918ecc9e3a75892169415d7f6c95b591b6a52d"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Better Auth OAuth Provider: Refresh Token Rotation Race Condition Allows Concurrent Replay and Token Family Forking"
}