{"id":"GHSA-f43r-cc68-gpx4","summary":"External Control of File Name or Path in Langflow","details":"**Vulnerability Overview**\n\nIf an arbitrary path is specified in the request body's `fs_path`, the server serializes the Flow object into JSON and creates/overwrites a file at that path. There is no path restriction, normalization, or allowed directory enforcement, so absolute paths (e.g., /etc/poc.txt) are interpreted as is.\n\n**Vulnerable Code**\n\n1. It receives the request body (flow), updates the DB, and then passes it to the file-writing sink.\n    \n    https://github.com/langflow-ai/langflow/blob/ac6e2d2eabeee28085f2739d79f7ce4205ca082c/src/backend/base/langflow/api/v1/flows.py#L154-L168\n    \n    ```python\n    @router.post(\"/\", response_model=FlowRead, status_code=201)\n    async def create_flow(\n        *,\n        session: DbSession,\n        flow: FlowCreate,\n        current_user: CurrentActiveUser,\n    ):\n        try:\n            db_flow = await _new_flow(session=session, flow=flow, user_id=current_user.id)\n            await session.commit()\n            await session.refresh(db_flow)\n    \n            await _save_flow_to_fs(db_flow)\n    \n        except Exception as e:\n    ```\n    \n2. Applies authentication dependency (requires API Key/JWT) when accessing the endpoint.\n    \n    https://github.com/langflow-ai/langflow/blob/ac6e2d2eabeee28085f2739d79f7ce4205ca082c/src/backend/base/langflow/api/utils/core.py#L36-L38\n    \n    ```python\n    CurrentActiveUser = Annotated[User, Depends(get_current_active_user)]\n    CurrentActiveMCPUser = Annotated[User, Depends(get_current_active_user_mcp)]\n    DbSession = Annotated[AsyncSession, Depends(get_session)]\n    ```\n    \n3. The client can directly specify the save path, including `fs_path`.\n    \n    https://github.com/langflow-ai/langflow/blob/ac6e2d2eabeee28085f2739d79f7ce4205ca082c/src/backend/base/langflow/api/v1/flows.py#L66-L70\n    \n    ```python\n    ):\n        try:\n            await _verify_fs_path(flow.fs_path)\n    \n            \"\"\"Create a new flow.\"\"\"\n    ```\n    \n4. It attempts to create the file (or *the* file, in the case of a path without a parent) directly without path validation.\n    \n    https://github.com/langflow-ai/langflow/blob/ac6e2d2eabeee28085f2739d79f7ce4205ca082c/src/backend/base/langflow/api/v1/flows.py#L45-L49\n    \n    ```python\n    async def _verify_fs_path(path: str | None) -\u003e None:\n        if path:\n            path_ = Path(path)\n            if not await path_.exists():\n                await path_.touch()\n    ```\n    \n5. Serializes the Flow object to JSON and writes it to the specified path in \"w\" mode (overwriting).\n    \n    https://github.com/langflow-ai/langflow/blob/ac6e2d2eabeee28085f2739d79f7ce4205ca082c/src/backend/base/langflow/api/v1/flows.py#L52-L58\n    \n    ```python\n    async def _save_flow_to_fs(flow: Flow) -\u003e None:\n        if flow.fs_path:\n            async with async_open(flow.fs_path, \"w\") as f:\n                try:\n                    await f.write(flow.model_dump_json())\n                except OSError:\n                    await logger.aexception(\"Failed to write flow %s to path %s\", flow.name, flow.fs_path)\n    ```\n    \n\n**PoC Description**\n\nWhen an authenticated user passes an arbitrary path in `fs_path`, the Flow JSON is written to that path. Since `/tmp` is usually writable, it is easy to reproduce. In a production environment, writing to system-protected directories may fail depending on permissions.\n\n**PoC**\n\n- **Before Exploit**\n   \n\n    \u003cimg width=\"1918\" height=\"658\" alt=\"image\" src=\"https://github.com/user-attachments/assets/fe3c2306-091d-4cb0-b4dc-c7fb63c03d8d\" /\u003e\n    \n- **After Exploit**\n    \n    ```bash\n    curl -sS -X POST \"http://localhost:7860/api/v1/flows/\" \\\n      -H \"Content-Type: application/json\" \\\n      -H \"x-api-key: sk-8Kyzf9IQ-UEJ_OtSTaJq4eniMT9_JKgZ7__q8PNkoxc\" \\\n      -d '{\"name\":\"poc-etc\",\"data\":{\"nodes\":[],\"edges\":[]},\"fs_path\":\"/tmp/POC.txt\"}'\n    ```\n    \n    \u003cimg width=\"1918\" height=\"742\" alt=\"image\" src=\"https://github.com/user-attachments/assets/cc0b0c96-1c2d-4d56-b558-5ba97e0ec174\" /\u003e\n    \n\n### Impact\n\n- **Authenticated Arbitrary File Write (within server permission scope):** Risk of corrupting configuration/log/task files, disrupting application behavior, and tampering with files read by other components.\n- **Both absolute and relative paths are allowed, enabling base directory traversal.** The risk of overwriting system files increases in environments with root privileges or weak mount/permission settings.\n- **The file content is limited to Flow JSON,** but the impact is severe if the target file is parsed by a JSON parser or is subject to subsequent processing.\n- **In production environments, it is essential to enforce a save root, normalize paths, block symlink traversal, and minimize permissions.**","aliases":["CVE-2025-68478","PYSEC-2025-125"],"modified":"2026-06-06T00:45:48.719106148Z","published":"2025-12-19T22:53:13Z","database_specific":{"cwe_ids":["CWE-610","CWE-73"],"severity":"HIGH","github_reviewed":true,"github_reviewed_at":"2025-12-19T22:53:13Z","nvd_published_at":"2025-12-19T18:15:51Z"},"references":[{"type":"WEB","url":"https://github.com/langflow-ai/langflow/security/advisories/GHSA-f43r-cc68-gpx4"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-68478"},{"type":"PACKAGE","url":"https://github.com/langflow-ai/langflow"},{"type":"WEB","url":"https://github.com/pypa/advisory-database/tree/main/vulns/langflow/PYSEC-2025-125.yaml"}],"affected":[{"package":{"name":"langflow","ecosystem":"PyPI","purl":"pkg:pypi/langflow"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.7.1"}]}],"versions":["0.0.31","0.0.32","0.0.33","0.0.40","0.0.44","0.0.45","0.0.46","0.0.52","0.0.53","0.0.54","0.0.55","0.0.56","0.0.57","0.0.58","0.0.61","0.0.62","0.0.63","0.0.64","0.0.65","0.0.66","0.0.67","0.0.68","0.0.69","0.0.70","0.0.71","0.0.72","0.0.73","0.0.74","0.0.75","0.0.76","0.0.78","0.0.79","0.0.80","0.0.81","0.0.83","0.0.84","0.0.85","0.0.86","0.0.87","0.0.88","0.0.89","0.1.0","0.1.2","0.1.3","0.1.4","0.1.5","0.1.6","0.1.7","0.2.0","0.2.1","0.2.10","0.2.11","0.2.12","0.2.13","0.2.2","0.2.3","0.2.4","0.2.5","0.2.6","0.2.7","0.2.8","0.2.9","0.3.0","0.3.1","0.3.2","0.3.3","0.3.4","0.4.0","0.4.1","0.4.10","0.4.11","0.4.12","0.4.14","0.4.15","0.4.16","0.4.17","0.4.18","0.4.19","0.4.2","0.4.20","0.4.21","0.4.3","0.4.4","0.4.5","0.4.6","0.4.7","0.4.8","0.4.9","0.5.0","0.5.0a0","0.5.0a1","0.5.0a2","0.5.0a3","0.5.0a4","0.5.0a5","0.5.0a6","0.5.0b0","0.5.0b2","0.5.0b3","0.5.0b4","0.5.0b5","0.5.0b6","0.5.1","0.5.10","0.5.11","0.5.12","0.5.2","0.5.3","0.5.4","0.5.5","0.5.6","0.5.7","0.5.8","0.5.9","0.6.0","0.6.0rc1","0.6.1","0.6.10","0.6.11","0.6.12","0.6.14","0.6.15","0.6.16","0.6.17","0.6.18","0.6.19","0.6.2","0.6.3","0.6.3a0","0.6.3a1","0.6.3a2","0.6.3a3","0.6.3a4","0.6.3a5","0.6.3a6","0.6.3a7","0.6.4","0.6.4a0","0.6.4a1","0.6.5","0.6.5a0","0.6.5a1","0.6.5a10","0.6.5a11","0.6.5a12","0.6.5a13","0.6.5a2","0.6.5a3","0.6.5a4","0.6.5a5","0.6.5a6","0.6.5a7","0.6.5a8","0.6.5a9","0.6.6","0.6.7","0.6.7a1","0.6.7a2","0.6.7a3","0.6.7a5","0.6.8","0.6.9","1.0.0","1.0.0a0","1.0.0a1","1.0.0a10","1.0.0a11","1.0.0a12","1.0.0a13","1.0.0a14","1.0.0a15","1.0.0a17","1.0.0a18","1.0.0a19","1.0.0a2","1.0.0a20","1.0.0a21","1.0.0a22","1.0.0a23","1.0.0a24","1.0.0a25","1.0.0a26","1.0.0a27","1.0.0a28","1.0.0a29","1.0.0a3","1.0.0a30","1.0.0a31","1.0.0a32","1.0.0a33","1.0.0a34","1.0.0a35","1.0.0a36","1.0.0a37","1.0.0a38","1.0.0a39","1.0.0a4","1.0.0a40","1.0.0a41","1.0.0a42","1.0.0a43","1.0.0a44","1.0.0a45","1.0.0a46","1.0.0a47","1.0.0a48","1.0.0a49","1.0.0a5","1.0.0a50","1.0.0a51","1.0.0a52","1.0.0a53","1.0.0a55","1.0.0a56","1.0.0a57","1.0.0a58","1.0.0a59","1.0.0a6","1.0.0a60","1.0.0a61","1.0.0a7","1.0.0a8","1.0.0a9","1.0.0rc0","1.0.0rc1","1.0.1","1.0.10","1.0.11","1.0.12","1.0.13","1.0.14","1.0.15","1.0.16","1.0.17","1.0.18","1.0.19","1.0.19.post1","1.0.19.post2","1.0.2","1.0.3","1.0.4","1.0.5","1.0.6","1.0.7","1.0.8","1.0.9","1.1.0","1.1.1","1.1.2","1.1.3","1.1.4","1.1.4.post1","1.2.0","1.3.0","1.3.1","1.3.2","1.3.3","1.3.4","1.4.0","1.4.1","1.4.2","1.4.3","1.5.0","1.5.0.post1","1.5.0.post2","1.5.1","1.6.0","1.6.1","1.6.2","1.6.3","1.6.4","1.6.5","1.6.6","1.6.7","1.6.8","1.6.9","1.7.0"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2025/12/GHSA-f43r-cc68-gpx4/GHSA-f43r-cc68-gpx4.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L"}]}