{"id":"CVE-2026-112947","aliases":["GHSA-vfpm-58rq-9qcg"],"url":"https://o3.security/vulnerability/CVE-2026-112947","summary":"Vite: First 4 bytes of files outside of `server.fs` setting is exposed by `?vite-wasm-instance`","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's 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's `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 'SECRET_KEY=abc123\\n' > .env\nnpm run dev\ncurl 'http://localhost:5173/.env?vite-wasm-instance'\n```\n\nThis will show\n```\nFailed to parse WASM file \"<root>/.env\": WebAssembly.compile(): expected magic word 00 61 73 6d, found 53 45 43 52 @+0\n```","published":"2026-10-20T15:10:51.025Z","modified":"2026-10-24T02:49:28.987232394Z","cvss":null,"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"npm","name":"vite","fixedVersion":"8.3.3"},{"ecosystem":"npm","name":"vite","fixedVersion":"8.2.4"},{"ecosystem":"npm","name":"vite-plus","fixedVersion":"1.1.0"}],"fix":{"url":"https://github.com/vitejs/vite/commit/b6c6d2fb3f853aab4092dc25f0d6816a96c23dff","label":"vitejs/vite@b6c6d2f"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/112xxx/CVE-2026-112947.json"},{"type":"ADVISORY","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":"FIX","url":"https://github.com/vitejs/vite/commit/b6c6d2fb3f853aab4092dc25f0d6816a96c23dff"},{"type":"FIX","url":"https://github.com/vitejs/vite/commit/ba8b7ab43b4afa5d0292ab4b6e3a7b5033cc9c73"},{"type":"FIX","url":"https://github.com/vitejs/vite/pull/23655"},{"type":"PACKAGE","url":"https://github.com/vitejs/vite"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-10-24T02:49:28.987232394Z"}}