Vulnerability · Published Oct 5, 2026 · Assigned by GitHub_M
CVE-2026-105697Langflow: OS command injection (RCE) via arbitrary command in MCP stdio server configuration
Critical 9.9
In plain English
A critical-severity OS command injection in langflow from langflow-ai. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.9% (higher than 61% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code. Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| PyPI | langflow | 1.10.3 | GHSA-w794-rj3p-xv45 |
| PyPI | langflow | 1.10.3 | PYSEC-2026-4237 |
| PyPI | langflow-base | 0.10.3 | GHSA-w794-rj3p-xv45 |
| PyPI | langflow-base | 0.10.3 | PYSEC-2026-4239 |
| PyPI | lfx | 1.10.3 | GHSA-w794-rj3p-xv45 |
| PyPI | lfx | 1.10.3 | PYSEC-2026-4241 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| langflow-ai | langflow | >= 1.1.2, < 1.10.3 |
| langflow-ai | langflow-base | >= 0.1.2, < 0.10.3 |
| langflow-ai | lfx | < 1.10.3 |
Weakness: CWE-78 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
References
- https://github.com/langflow-ai/langflow/security/advisories/GHSA-w794-rj3p-xv45 x_refsource_CONFIRM
- https://github.com/langflow-ai/langflow/security/advisories/GHSA-7w94-79vh-5mr2 x_refsource_MISC
- https://github.com/langflow-ai/langflow/pull/12290 x_refsource_MISC
- https://github.com/langflow-ai/langflow/pull/14036 x_refsource_MISC
- https://github.com/langflow-ai/langflow/commit/eba285edf1dd4a33bf23a9cb8113c991fcdf3d1d x_refsource_MISC
- https://github.com/langflow-ai/langflow/commit/efbc4a16e639409d938a4883463d27ef0bc637a0 x_refsource_MISC
- https://github.com/langflow-ai/langflow/releases/tag/v1.10.3 x_refsource_MISC
- https://www.ox.security/blog/mcp-supply-chain-advisory-rce-vulnerabilities-across-the-ai-ecosystem x_refsource_MISC
- https://www.ox.security/blog/the-mother-of-all-ai-supply-chains-critical-systemic-vulnerability-at-the-core-of-the-mcp x_refsource_MISC