{
  "canonical_id": "nextjs--CVE-2021-39178",
  "system_id": "nextjs",
  "display_name": "Next.js",
  "category": "frameworks",
  "advisory_mode": "core",
  "title": "XSS in Image Optimization API for Next.js",
  "summary": "### Impact\n- **Affected:** All of the following must be true to be affected\n    - Next.js between version 10.0.0 and 11.1.0\n    - The `next.config.js` file has [`images.domains`](https://nextjs.org/docs/basic-features/image-optimization#domains) array assigned\n    - The image host assigned in [`images.domains`](https://nextjs.org/docs/basic-features/image-optimization#domains) allows user-provided SVG\n- **Not affected**: The `next.config.js` file has [`images.loader`](https://nextjs.org/docs/basic-features/image-optimization#loader) assigned to something other than default\n- **Not affected**: Deployments on [Vercel](https://vercel.com) are not affected\n\n### Patches\n[Next.js v11.1.1](https://github.com/vercel/next.js/releases/tag/v11.1.1)\n\n",
  "published_at": "2021-09-01T18:24:22Z",
  "updated_at": "2026-03-13T22:00:20.154452Z",
  "severity": "low",
  "cvss_score": 3.1,
  "exploit_status": "unknown",
  "source_confidence": "official",
  "official_source_url": "https://github.com/vercel/next.js/security/advisories/GHSA-9gr3-7897-pp7m",
  "secondary_source_urls": [
    "https://nvd.nist.gov/vuln/detail/CVE-2021-39178",
    "https://github.com/vercel/next.js/pull/28620",
    "https://github.com/vercel/next.js/commit/7afc97c5744b38bdf36aa7f87625f438224688aa",
    "https://github.com/vercel/next.js",
    "https://github.com/vercel/next.js/releases/tag/v11.1.1"
  ],
  "aliases": [
    "CVE-2021-39178",
    "GHSA-9gr3-7897-pp7m"
  ],
  "cve_ids": [
    "CVE-2021-39178"
  ],
  "ghsa_ids": [
    "GHSA-9gr3-7897-pp7m"
  ],
  "osv_ids": [
    "GHSA-9gr3-7897-pp7m"
  ],
  "affected_versions": [
    "introduced=10.0.0, fixed<11.1.1"
  ],
  "fixed_versions": [
    "11.1.1"
  ],
  "package_name": "next",
  "render_markdown": true,
  "case_path": "07-framework-security/frameworks/nextjs/cases/nextjs-cve-2021-39178.md",
  "secure_code_topics": [
    "authz-server-side-recheck",
    "proxy-trust-boundary",
    "token-cookie-storage",
    "xss-output-encoding"
  ],
  "status": "generated",
  "triage_reasons": [],
  "verification_status": "verified-real",
  "verification_mode": "real",
  "last_verified_at": "2026-03-18T03:56:42+00:00",
  "last_run_id": "nextjs-nextjs--CVE-2021-39178-20260318035635",
  "evidence_bundle": "/Users/x/websafe/06-case-studies/generated-runs/nextjs-nextjs--CVE-2021-39178-20260318035635",
  "historical_status": "verified-real",
  "latest_status": "verified-real",
  "browser_evidence": {
    "required": false,
    "present": true,
    "refs": [
      "/Users/x/websafe/06-case-studies/generated-runs/nextjs-nextjs--CVE-2021-39178-20260318035635/assets/baseline.png",
      "/Users/x/websafe/06-case-studies/generated-runs/nextjs-nextjs--CVE-2021-39178-20260318035635/assets/baseline-dom.html",
      "/Users/x/websafe/06-case-studies/generated-runs/nextjs-nextjs--CVE-2021-39178-20260318035635/logs/baseline-console.json",
      "/Users/x/websafe/06-case-studies/generated-runs/nextjs-nextjs--CVE-2021-39178-20260318035635/logs/baseline-network.json",
      "/Users/x/websafe/06-case-studies/generated-runs/nextjs-nextjs--CVE-2021-39178-20260318035635/logs/baseline-page.json",
      "/Users/x/websafe/06-case-studies/generated-runs/nextjs-nextjs--CVE-2021-39178-20260318035635/assets/proof.png",
      "/Users/x/websafe/06-case-studies/generated-runs/nextjs-nextjs--CVE-2021-39178-20260318035635/assets/proof-dom.html",
      "/Users/x/websafe/06-case-studies/generated-runs/nextjs-nextjs--CVE-2021-39178-20260318035635/logs/proof-console.json",
      "/Users/x/websafe/06-case-studies/generated-runs/nextjs-nextjs--CVE-2021-39178-20260318035635/logs/proof-network.json",
      "/Users/x/websafe/06-case-studies/generated-runs/nextjs-nextjs--CVE-2021-39178-20260318035635/logs/proof-page.json"
    ]
  },
  "repro_profile_id": "nextjs-xss",
  "artifact_mode": "local-fixture",
  "blocked_reason": null,
  "metadata": {
    "source_names": [
      "OSV Next.js"
    ],
    "source_kinds": [
      "osv-batch"
    ],
    "candidate_count": 1
  }
}