{"id":"GHSA-vfpm-58rq-9qcg","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' \u003e .env\nnpm run dev\ncurl 'http://localhost:5173/.env?vite-wasm-instance'\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```","aliases":["CVE-2026-112947"],"modified":"2026-10-21T17:00:07.443467820Z","published":"2026-10-21T16:47:15Z","database_specific":{"severity":"MODERATE","github_reviewed":true,"github_reviewed_at":"2026-10-21T16:47:15Z","nvd_published_at":"2026-10-20T16:17:05Z","cwe_ids":["CWE-200","CWE-209","CWE-22"]},"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"}],"affected":[{"package":{"name":"vite","ecosystem":"npm","purl":"pkg:npm/vite"},"ranges":[{"type":"SEMVER","events":[{"introduced":"8.3.0"},{"fixed":"8.3.3"}]}],"database_specific":{"last_known_affected_version_range":"\u003c= 8.3.2","source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/10/GHSA-vfpm-58rq-9qcg/GHSA-vfpm-58rq-9qcg.json"}},{"package":{"name":"vite","ecosystem":"npm","purl":"pkg:npm/vite"},"ranges":[{"type":"SEMVER","events":[{"introduced":"8.2.0"},{"fixed":"8.2.4"}]}],"database_specific":{"last_known_affected_version_range":"\u003c= 8.2.3","source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/10/GHSA-vfpm-58rq-9qcg/GHSA-vfpm-58rq-9qcg.json"}},{"package":{"name":"vite-plus","ecosystem":"npm","purl":"pkg:npm/vite-plus"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0.2.8"},{"fixed":"1.1.0"}]}],"database_specific":{"last_known_affected_version_range":"\u003c= 1.0.0","source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/10/GHSA-vfpm-58rq-9qcg/GHSA-vfpm-58rq-9qcg.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","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"}]}