{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "1.4.0"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "DESCRIPTION"
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "bff00f6b7fb3d95363888186cd610ea3e4e0f174"
            }
          ],
          "repo": "https://github.com/better-auth/better-auth",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-wmjr-v86c-m9jj"
  ],
  "database_specific": {
    "cna_assigner": "VulnCheck",
    "cwe_ids": [
      "CWE-347"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/71xxx/CVE-2025-71402.json"
  },
  "details": "better-auth versions greater than 1.3.34 and before 1.4.0 contain a vulnerability in the multi-session plugin's /sign-out after-hook, which trusts raw multi-session cookies and forwards extracted values to internalAdapter.deleteSessions without verifying the cookie signature (e.g., via getSignedCookie). An attacker can supply a forged _multi-* cookie to trigger deletion of arbitrary session tokens.",
  "id": "CVE-2025-71402",
  "modified": "2026-08-04T03:32:23.018882415Z",
  "published": "2026-08-01T12:22:16.655Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/71xxx/CVE-2025-71402.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/better-auth/better-auth/security/advisories/GHSA-wmjr-v86c-m9jj"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-71402"
    },
    {
      "type": "ADVISORY",
      "url": "https://www.vulncheck.com/advisories/better-auth-before-session-revocation-via-forged-cookie"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:L/VI:L/VA:L/SC:L/SI:L/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "better-auth before 1.4.0 Session Revocation via Forged Cookie"
}