BREW-VITE-CVE-2026-112947 (GHSA-VFPM-58RQ-9QCG)

Vulnerability from osv_homebrew – Published: 2026-10-22 11:18 – Updated: 2026-10-23 10:23 – Source website
VLAI
Summary
Vite: First 4 bytes of files outside of `server.fs` setting is exposed by `?vite-wasm-instance`
Details

Summary

The first 4 bytes of files outside of server.fs setting can be returned to the browser by a request containing ?vite-wasm-instance.

Impact

Only apps that match one of the following conditions are affected:

  • explicitly expose the Vite dev server to the network using --host or the server.host option
  • there's a file that has a sensitive information in the first 4 bytes
  • uses Node.js or Deno to run Vite (if Bun is used, it is not affected)

Details

Requests containing the ?vite-wasm-instance query are handled by the internal Wasm plugin's load hook. The hook removes the query and reads the resulting path directly from disk, but the server.fs checks were not applied.

After reading the file, Vite attempts to parse it as WebAssembly. When that parse fails, Node and deno throws an error that contains the first 4 bytes of the file.

PoC

Create a denied file and start an affected Vite dev server:

echo 'SECRET_KEY=abc123\n' > .env
npm run dev
curl 'http://localhost:5173/.env?vite-wasm-instance'

This will show

Failed to parse WASM file "<root>/.env": WebAssembly.compile(): expected magic word 00 61 73 6d, found 53 45 43 52 @+0
Severity
6.3 (Medium)
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "fix": "bump",
        "range_state": "fixed",
        "upstream_fixed_in": "8.3.3"
      },
      "package": {
        "ecosystem": "Homebrew",
        "name": "vite",
        "purl": "pkg:brew/vite"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "8.2.0"
            },
            {
              "fixed": "8.3.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "confidence": "high",
    "source": "matched",
    "strategy": "registry",
    "upstream_evidence": [
      {
        "ecosystem": "npm",
        "key": "pkg:npm/vite@8.3.5",
        "name": "vite",
        "strategy": "registry",
        "subject_version": "8.3.5"
      }
    ]
  },
  "details": "### Summary\n\nThe first 4 bytes of files outside of `server.fs` setting can be returned to the browser by a request containing `?vite-wasm-instance`.\n\n### Impact\n\n Only apps that match one of the following conditions are affected:\n\n- explicitly expose the Vite dev server to the network using `--host` or the [`server.host`](https://vite.dev/config/server-options#server-host) option\n- there\u0027s a file that has a sensitive information in **the first 4 bytes**\n- uses Node.js or Deno to run Vite (if Bun is used, it is not affected)\n\n### Details\nRequests containing the `?vite-wasm-instance` query are handled by the internal Wasm plugin\u0027s `load` hook. The hook removes the query and reads the resulting path directly from disk, but the `server.fs` checks were not applied.\n\nAfter reading the file, Vite attempts to parse it as WebAssembly. When that parse fails, Node and deno throws an error that contains the first 4 bytes of the file.\n\n### PoC\n\nCreate a denied file and start an affected Vite dev server:\n\n```bash\necho \u0027SECRET_KEY=abc123\\n\u0027 \u003e .env\nnpm run dev\ncurl \u0027http://localhost:5173/.env?vite-wasm-instance\u0027\n```\n\nThis will show\n```\nFailed to parse WASM file \"\u003croot\u003e/.env\": WebAssembly.compile(): expected magic word 00 61 73 6d, found 53 45 43 52 @+0\n```",
  "id": "BREW-vite-CVE-2026-112947",
  "modified": "2026-10-23T10:23:51Z",
  "published": "2026-10-22T11:18:44Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/vitejs/vite/security/advisories/GHSA-vfpm-58rq-9qcg"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-112947"
    },
    {
      "type": "WEB",
      "url": "https://github.com/vitejs/vite/pull/23655"
    },
    {
      "type": "WEB",
      "url": "https://github.com/vitejs/vite/commit/b6c6d2fb3f853aab4092dc25f0d6816a96c23dff"
    },
    {
      "type": "WEB",
      "url": "https://github.com/vitejs/vite/commit/ba8b7ab43b4afa5d0292ab4b6e3a7b5033cc9c73"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/vitejs/vite"
    }
  ],
  "schema_version": "1.7.3",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Vite: First 4 bytes of files outside of `server.fs` setting is exposed by `?vite-wasm-instance`",
  "upstream": [
    "GHSA-vfpm-58rq-9qcg",
    "CVE-2026-112947"
  ]
}



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