GHSA-9PGF-384G-P7MV

Vulnerability from github – Published: 2026-08-05 21:43 – Updated: 2026-08-05 21:43
VLAI
Summary
Nuxt: Unauthenticated CPU exhaustion parsing and hashing the Nuxt island endpoint body before hash validation
Details

Impact

The internal island renderer endpoint (/__nuxt_island/...) decodes and hashes attacker-controlled request input before it validates the URL-resident hash. An unauthenticated POST /__nuxt_island/<name>_<anything>.json with a large JSON body (for example ~4.6 MB / 150k keys) is fully read, destr-parsed, and run through ohash before the request is rejected with a 400. Because Nitro runs on a single event loop, this both wastes CPU on the doomed request and delays every concurrent request. A low request rate is enough to degrade or stall the server. No valid hash and no authentication are required.

Patches

Fixed in nuxt@4.5.1 and nuxt@3.21.10. The island handler now enforces a raw body-size cap (413) and a JSON nesting-depth cap (400) before parsing or hashing, so oversized or deeply nested input is rejected cheaply.

Workarounds

Put a small request-body limit in front of /__nuxt_island/ at your reverse proxy / edge (islands legitimately send only a compact props payload), or disable server components if unused.

Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Show details on source website
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{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "nuxt"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.0.0"
            },
            {
              "fixed": "4.5.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "nuxt"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "3.1.0"
            },
            {
              "fixed": "3.21.10"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-71321"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-407",
      "CWE-770"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-08-05T21:43:03Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "### Impact\n\nThe internal island renderer endpoint (`/__nuxt_island/...`) decodes and hashes attacker-controlled request input before it validates the URL-resident hash. An unauthenticated `POST /__nuxt_island/\u003cname\u003e_\u003canything\u003e.json` with a large JSON body (for example ~4.6 MB / 150k keys) is fully read, `destr`-parsed, and run through `ohash` before the request is rejected with a 400. Because Nitro runs on a single event loop, this both wastes CPU on the doomed request and delays every concurrent request. A low request rate is enough to degrade or stall the server. No valid hash and no authentication are required.\n\n### Patches\n\nFixed in `nuxt@4.5.1` and `nuxt@3.21.10`. The island handler now enforces a raw body-size cap (`413`) and a JSON nesting-depth cap (`400`) before parsing or hashing, so oversized or deeply nested input is rejected cheaply.\n\n### Workarounds\n\nPut a small request-body limit in front of `/__nuxt_island/` at your reverse proxy / edge (islands legitimately send only a compact props payload), or disable server components if unused.",
  "id": "GHSA-9pgf-384g-p7mv",
  "modified": "2026-08-05T21:43:03Z",
  "published": "2026-08-05T21:43:03Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/nuxt/nuxt/security/advisories/GHSA-9pgf-384g-p7mv"
    },
    {
      "type": "WEB",
      "url": "https://github.com/nuxt/nuxt/commit/4e35ae9babd94be53246e31200232d48438bb34e"
    },
    {
      "type": "WEB",
      "url": "https://github.com/nuxt/nuxt/commit/668cdfdfda41849ed11c1ee5e2067a11fc103b22"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/nuxt/nuxt"
    },
    {
      "type": "WEB",
      "url": "https://github.com/nuxt/nuxt/releases/tag/v3.21.10"
    },
    {
      "type": "WEB",
      "url": "https://github.com/nuxt/nuxt/releases/tag/v4.5.1"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Nuxt: Unauthenticated CPU exhaustion parsing and hashing the Nuxt island endpoint body before hash validation"
}



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