CVE-2025-59414: Nuxt Path Traversal Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-p6jq-8vc4-79f6",
  "modified" : "2025-09-18T13:04:21Z",
  "published" : "2025-09-17T20:42:28Z",
  "aliases" : [ "CVE-2025-59414" ],
  "summary" : "Nuxt has Client-Side Path Traversal in Nuxt Island Payload Revival",
  "details" : "### Summary\n\nA client-side path traversal vulnerability in Nuxt's Island payload revival mechanism allowed attackers to manipulate client-side requests to different endpoints within the same application domain when specific prerendering conditions are met.\n\n### Technical Details\n\nThe vulnerability occurs in the client-side payload revival process (revive-payload.client.ts) where Nuxt Islands are automatically fetched when encountering serialized `__nuxt_island` objects. The issue affects the following flow:\n\n1. During prerendering, if an API endpoint returns user-controlled data containing a crafted `__nuxt_island` object\n2. This data gets serialized with `devalue.stringify` and stored in the prerendered page\n3. When a client navigates to the prerendered page, `devalue.parse` deserializes the payload\n4. The Island reviver attempts to fetch `/__nuxt_island/${key}.json` where `key` could contain path traversal sequences\n\n### Prerequisites for Exploitation\n\nThis vulnerability requires **all** of the following conditions:\n\n1. **Prerendered pages**: The application must use Nuxt's prerendering feature (`nitro.prerender`)\n2. **Attacker-controlled API responses**: The attacker must be able to control the response content of an API endpoint that is called during prerendering via `useFetch`, `useAsyncData`, or similar composables\n3. **Client-side navigation**: A user must navigate to the prerendered page (not during initial SSR hydration)\n\n### Attack Scenario\n\n```javascript\n// Malicious API response during prerendering\n{\n  \"__nuxt_island\": {\n    \"key\": \"../../../../internal/service\",\n    \"params\": { \"action\": \"probe\" }\n  }\n}\n```\n\nThis could cause the client to make requests to `/__nuxt_island/../../../../internal/service.json` if path traversal is not properly handled by the server.\n\n### Impact Assessment\n\n- **Limited Impact**: The vulnerability has a low severity due to the highly specific prerequisites\n- **No Direct Data Exfiltration**: The vulnerability does not directly expose sensitive data\n- **Client-Side Only**: Requests originate from the client, not the server\n\n### Mitigation\n\n**Action Required:**\n- Update to Nuxt 3.19.0+ or 4.1.0+ immediately\n- Review any prerendered pages that fetch external or user-controlled data\n\n**Temporary Workarounds** (if immediate update is not possible):\n1. Disable prerendering for pages that fetch user-controlled data\n2. Implement strict input validation on API endpoints used during prerendering\n3. Use allowlists for API response structures during prerendering\n\n### Fix Details\n\n[The fix](https://github.com/nuxt/nuxt/commit/2566d2046bccb158d98fb13e42ce4b2c33fb2595) implemented validation for Island keys in `revive-payload.server.ts`:\n- Island keys must match the pattern `/^[a-z][a-z\\d-]*_[a-z\\d]+$/i`\n- Maximum length of 100 characters\n- Prevents path traversal and special characters",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "nuxt"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "3.6.0"
      }, {
        "fixed" : "3.19.0"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "npm",
      "name" : "nuxt"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "4.0.0"
      }, {
        "fixed" : "4.1.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/nuxt/nuxt/security/advisories/GHSA-p6jq-8vc4-79f6"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-59414"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/nuxt/nuxt/commit/2566d2046bccb158d98fb13e42ce4b2c33fb2595"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/nuxt/nuxt"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-22" ],
    "severity" : "LOW",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-09-17T20:42:28Z",
    "nvd_published_at" : "2025-09-17T19:15:47Z"
  }
}