{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "next"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "14.1.1"
            },
            {
              "fixed": "15.5.21"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "next"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "16.0.0"
            },
            {
              "fixed": "16.2.11"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-64649"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-918"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-22T23:09:48Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "## Impact\n\nWhen a Server Action forwards or redirects a request, an attacker can cause the server to send that outbound request to a malicious host (Server-Side Request Forgery). This requires the attacker\u0027s request to control Host-associated headers. In some configurations, it\u0027s also possible to obtain internal values that weaken middleware/proxy authorization.\n\nApplications that use Server Actions are affected when the incoming host header is not fixed to a trusted value. This typically occurs on custom servers, or on deployments not behind a proxy that pins the host. Managed hosting pins the host upstream and is not affected; `next start` and standalone output do the same from version 14.2 onward.\n\n## Workarounds\n\nIf you cannot upgrade, ensure clients do not control the host header your application receives. Pin or validate `Host` and `X-Forwarded-Host` at your edge or proxy. On version 14.2.0 and later, you can additionally set the `__NEXT_PRIVATE_ORIGIN` environment variable to your deployment\u0027s real origin:\n\n```bash\n__NEXT_PRIVATE_ORIGIN=https://www.example.com node server.js",
  "id": "GHSA-89xv-2m56-2m9x",
  "modified": "2026-07-22T23:09:48Z",
  "published": "2026-07-22T23:09:48Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/vercel/next.js/security/advisories/GHSA-89xv-2m56-2m9x"
    },
    {
      "type": "WEB",
      "url": "https://github.com/vercel/next.js/commit/b51206321854193208c0805ba42acc49287f942b"
    },
    {
      "type": "WEB",
      "url": "https://github.com/vercel/next.js/commit/e3e5666ccead3a15162793d697af5e48b7cc0498"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/vercel/next.js"
    },
    {
      "type": "WEB",
      "url": "https://github.com/vercel/next.js/releases/tag/v15.5.21"
    },
    {
      "type": "WEB",
      "url": "https://github.com/vercel/next.js/releases/tag/v16.2.11"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Next.js: Server-Side Request Forgery in Server Actions on custom servers"
}