{"id":"CVE-2026-10561","aliases":["GHSA-8qpj-27x8-pwpq"],"title":"Langflow: PythonREPLComponent executes unsandboxed Python code, enabling authenticated RCE and privilege escalation","summary":"Langflow: PythonREPLComponent executes unsandboxed Python code, enabling authenticated RCE and privilege escalation","severity":"critical","cvss":9.9,"cwe":["CWE-94","CWE-95","CWE-266"],"vendor":"langflow","product":"langflow","ecosystem":"pip","affected":["langflow < 1.10.1"],"patched":["langflow 1.10.1"],"published":"2026-10-06","updated":"2026-10-06","sourceUpdated":"2026-10-06T13:38:29Z","source":"GHSA","sourceUrl":"https://github.com/advisories/GHSA-8qpj-27x8-pwpq","references":[{"url":"https://github.com/langflow-ai/langflow/security/advisories/GHSA-8qpj-27x8-pwpq"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-10561"},{"url":"https://github.com/langflow-ai/langflow/pull/13700"},{"url":"https://github.com/langflow-ai/langflow/commit/2754c84aad1306f463db1c3bbb3e8ffbe85da77d"},{"url":"https://github.com/langflow-ai/langflow/releases/tag/v1.10.1"},{"url":"https://www.ibm.com/support/pages/node/7277242"},{"url":"https://github.com/advisories/GHSA-8qpj-27x8-pwpq"}],"tags":["ghsa","pip"],"epss":0.01003,"epssPercentile":0.61676,"ingestedAt":"2026-10-06T14:00:19.135Z","slug":"CVE-2026-10561","body":"## Overview\n\n### Summary\n\nLangflow's built-in Python interpreter components — `PythonREPLComponent` (Python Interpreter) and the legacy `PythonREPLToolComponent` (Python REPL Tool) — executed arbitrary user- or model-supplied Python code inside flows without effective sandboxing. Because the code ran in-process with the privileges of the Langflow service, any **authenticated** user who could edit and run a flow could achieve remote code execution and, from there, escalate privileges to superuser (e.g. by opening a database session and flipping `is_superuser`) or compromise the host.\n\n**This issue is fixed as of 1.10.1**, with additional hardening through 1.12.3. See *Remediation* below.\n\n### Affected\n\n- **Package:** `langflow` (PyPI), and the underlying `lfx` package that ships the component.\n- **Vulnerable versions:** `< 1.10.1`.\n- **Patched:** `1.10.1` (core fix). Upgrade to `>= 1.12.3` for the complete hardening series.\n\n### Details\n\nThe root cause is **code injection** (CWE-94/CWE-95): the component passed raw input to LangChain's `PythonREPL`, which is explicitly *not* a security sandbox.\n\nTwo distinct weaknesses existed before 1.10.1:\n\n1. **Unrestricted builtins (default deployments).** `get_globals()` built the `exec` globals from the `global_imports` allow-list but never set `__builtins__`. CPython's `exec()` then auto-injected the full `builtins` module, leaving `__import__`, `open`, `eval`, `exec` and the whole import machinery reachable regardless of the allow-list — e.g. `__import__(\"os\").system(...)` or `__import__(\"subprocess\").check_output([...])`. This made the \"only modules in Global Imports can be used\" guarantee false, and it applied even with the **default** configuration (`allow_custom_components=True`).\n\n2. **No server-policy gate (locked-down deployments).** Even a deployment hardened with `allow_custom_components=False` could still run interpreter code, because the components did not consult that policy before executing.\n\nBoth let an authenticated user run the reported PoC, which opens a DB session and sets `is_superuser = True` on their account, or writes to the filesystem / runs OS commands with the service's privileges.\n\n### PoC (as reported)\n\n1. Authenticate as a normal user.\n2. Create a flow with the `PythonREPLComponent`.\n3. Execute Python that imports Langflow internals and elevates the account:\n\n```python\nimport asyncio\nfrom sqlmodel import select\nfrom langflow.services.database.models.user.model import User\nfrom langflow.services.deps import session_scope\n\nasync def escalate():\n    async with session_scope() as session:\n        stmt = select(User).where(User.username == 'testuser')\n        user = (await session.exec(stmt)).first()\n        if user:\n            user.is_superuser = True\n            session.add(user)\n            await session.commit()\n\nasyncio.run(escalate())\n```\n\n### Impact\n\nAny authenticated user could:\n- Execute arbitrary Python / OS commands with the Langflow service's privileges (RCE).\n- Escalate their own account to superuser via direct database access.\n- Read/modify data and configuration, and potentially pivot to the underlying host.\n\n### Remediation\n\nUpgrade to **Langflow 1.10.1 or later** (preferably **>= 1.12.3**). The interpreter components were hardened with layered, defense-in-depth controls, applied in `run_python_repl()` before any code is executed:\n\n- **Restricted builtins** — `get_globals()` injects a curated `safe_builtins()` mapping, removing `__import__`, `eval`, `exec`, `compile`, `open`, `input`, `globals`/`locals`/`vars`, `getattr`/`setattr`, etc. (#13397)\n- **AST validation** — `validate_code_safety()` rejects inline `import`/`from ... import`, dunder/escape-gadget attribute access (`__class__`, `__subclasses__`, `__globals__`, frame/traceback introspection) and format-string dunder traversal. (#13397)\n- **Server-policy gate** — `ensure_code_execution_enabled()` refuses to run when `allow_custom_components=False` or `block_code_interpreter_components=True`, and **fails closed** if the settings stack cannot be resolved. (#13700 — this advisory — and #14375)\n- **Allow-listed module proxies** — imported modules are exposed via a proxy that blocks reaching `sys.modules[\"os\"]` through a module's transitive import graph. (#15198)\n- **Optional hardware isolation** — configure `LANGFLOW_SANDBOX_BACKEND` to run interpreter code in an isolated microVM instead of in-process. (#14400)\n\nUpstream fix references: #13397, #13700 (carries this GHSA), #14375, #14400, #15198.\n\n### Hardening recommendations for operators\n\n- Keep Langflow updated (>= 1.12.3).\n- For locked-down deployments, set `LANGFLOW_ALLOW_CUSTOM_COMPONENTS=false` (or `LANGFLOW_BLOCK_CODE_INTERPRETER_COMPONENTS=true`) to disable the interpreter entirely.\n- For deployments that must run untrusted code, configure `LANGFLOW_SANDBOX_BACKEND` for microVM isolation.\n- Run the Langflow service as an unprivileged user with least-privilege database credentials.\n\n## Affected packages\n\n- `langflow < 1.10.1`\n\n## Remediation\n\nUpgrade to a patched release:\n\n- `langflow 1.10.1`","depth":"midnight","depthScore":55,"depthScoreParts":{"impact":54.5,"likelihood":0.2,"exploitation":0,"ransomware":0},"changes":[]}