vulnerability / NVI-00011982 / Revision 1
Langflow: OS command injection (RCE) via arbitrary command in MCP stdio server configuration
GitHub lists this reviewed advisory for langflow, langflow-base, lfx. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
9.9 critical
GitHub source severity; exploitability and local consequence require separate evidence.
As of · GitHub Advisory Database
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
langflow
source listed>= 1.1.2, < 1.10.3
### Summary 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. The issue was fixed in two steps and is **fully fixed in Langflow 1.10.3** (and 1.11.0+): - **1.9.0** — #
langflow-base
source listed>= 0.1.2, < 0.10.3
### Summary 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. The issue was fixed in two steps and is **fully fixed in Langflow 1.10.3** (and 1.11.0+): - **1.9.0** — #
lfx
source listed< 1.10.3
### Summary 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. The issue was fixed in two steps and is **fully fixed in Langflow 1.10.3** (and 1.11.0+): - **1.9.0** — #
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-w794-rj3p-xv45 ↗
GitHub Advisory Database · vendor advisory
Observed . GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.
Public revision history
Only published revisions appear here. Routine fetches do not create a material-change event.
- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.