{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "5.0.0-beta.4"
              },
              {
                "fixed": "5.0.0-beta.32"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "0126f94788a263bd8420ceac9a11ed6d2c2fb958"
            },
            {
              "fixed": "d008b9b764bf4b322a87e1822d1dda7789258d8f"
            },
            {
              "fixed": "e293b3746616660f0844347a68d09eac54b95c6f"
            }
          ],
          "repo": "https://github.com/nextauthjs/next-auth",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-8fpg-xm3f-6cx3"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-285",
      "CWE-636"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/73xxx/CVE-2026-73421.json"
  },
  "details": "NextAuth.js provides authentication for Next.js. From next-auth 5.0.0-beta.0 until 5.0.0-beta.32, applications that gate access by checking only for the existence of the auth object returned by the auth() wrapper can fail open when Auth.js has a server configuration error. In middleware, Route Handlers, React Server Components, and other auth() entry points, a non-OK session response is parsed into a truthy error object instead of null, so checks such as !!auth and if (req.auth) evaluate to true for unauthenticated requests. A provider missing both the issuer and authorization endpoint triggers InvalidEndpoints, and an unset AUTH_SECRET or another server configuration error can produce the same behavior. There is no impact while configuration is valid, but after a deployment becomes misconfigured, routes protected only by session existence silently grant access to every visitor. This issue is fixed in next-auth 5.0.0-beta.32.",
  "id": "CVE-2026-73421",
  "modified": "2026-08-15T11:30:54.337769151Z",
  "published": "2026-08-13T22:04:36.985Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/nextauthjs/next-auth/releases/tag/next-auth@5.0.0-beta.32"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/73xxx/CVE-2026-73421.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/nextauthjs/next-auth/security/advisories/GHSA-8fpg-xm3f-6cx3"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-73421"
    },
    {
      "type": "FIX",
      "url": "https://github.com/nextauthjs/next-auth/commit/d008b9b764bf4b322a87e1822d1dda7789258d8f"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "NextAuth.js: Configuration errors can cause existence-based auth checks to fail open (auth object populated with an error)"
}