{"id":"CVE-2026-39365","aliases":["GHSA-4w7w-66w2-5vf9"],"url":"https://o3.security/vulnerability/CVE-2026-39365","summary":"Vite has a Path Traversal in Optimized Deps `.map` Handling","details":"### Summary\n\nAny files ending with `.map` even out side the project can be returned to the browser.\n\n### Impact\n\nOnly apps that match the following conditions are affected:\n\n- explicitly exposes the Vite dev server to the network (using `--host` or [`server.host` config option](https://vitejs.dev/config/server-options.html#server-host))\n- have a sensitive content in files ending with `.map` and the path is predictable\n\n### Details\n\nIn Vite v7.3.1, the dev server’s handling of `.map` requests for optimized dependencies resolves file paths and calls `readFile` without restricting `../` segments in the URL. As a result, it is possible to bypass the [`server.fs.strict`](https://vite.dev/config/server-options#server-fs-strict) allow list and retrieve `.map` files located outside the project root, provided they can be parsed as valid source map JSON.\n\n### PoC\n1. Create a minimal PoC sourcemap outside the project root\n    ```bash\n    cat > /tmp/poc.map <<'EOF'\n    {\"version\":3,\"file\":\"x.js\",\"sources\":[],\"names\":[],\"mappings\":\"\"}\n    EOF\n    ```\n2. Start the Vite dev server (example)\n    ```bash\n    pnpm -C playground/fs-serve dev --host 127.0.0.1 --port 18080\n    ```\n3. Confirm that direct `/@fs` access is blocked by `strict` (returns 403)\n    <img width=\"4004\" height=\"1038\" alt=\"image\" src=\"https://github.com/user-attachments/assets/15a859a8-1dc6-4105-8d58-80527c0dd9ab\" />\n4. Inject `../` segments under the optimized deps `.map` URL prefix to reach `/tmp/poc.map`\n    <img width=\"2790\" height=\"846\" alt=\"image\" src=\"https://github.com/user-attachments/assets/5d02957d-2e6a-4c45-9819-3f024e0e81f2\" />","published":"2026-04-07T19:13:50.927Z","modified":"2026-08-12T03:51:35.933534380Z","cvss":null,"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"vite","fixedVersion":"8.0.5"},{"ecosystem":"npm","name":"vite","fixedVersion":"7.3.2"},{"ecosystem":"npm","name":"vite","fixedVersion":"6.4.2"}],"fix":{"url":"https://github.com/vitejs/vite/pull/22161","label":"vitejs/vite#22161"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/39xxx/CVE-2026-39365.json"},{"type":"ADVISORY","url":"https://github.com/vitejs/vite/security/advisories/GHSA-4w7w-66w2-5vf9"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-39365"},{"type":"WEB","url":"https://github.com/vitejs/vite/pull/22161"},{"type":"WEB","url":"https://github.com/vitejs/vite/commit/79f002f2286c03c88c7b74c511c7f9fc6dc46694"},{"type":"PACKAGE","url":"https://github.com/vitejs/vite"},{"type":"WEB","url":"https://github.com/vitejs/vite/releases/tag/v6.4.2"},{"type":"WEB","url":"https://github.com/vitejs/vite/releases/tag/v7.3.2"},{"type":"WEB","url":"https://github.com/vitejs/vite/releases/tag/v8.0.5"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:35.933534380Z"}}