Description
Langflow is a tool for building and deploying AI-powered agents and workflows. Prior to 1.9.0, any authenticated Langflow user can achieve Remote Code Execution (RCE) on the server by adding an MCP server with the "Stdio" transport. The user-supplied command field is passed directly to bash -c "exec {command}" with zero validation, no allowlisting, and no sandboxing. The command executes immediately when the server list is fetched. Additionally, the env field allows arbitrary environment variable injection (e.g., LD_PRELOAD, PATH override). This vulnerability is fixed in 1.9.0.
References6
- github.com/langflow-ai/langflow/commit/efbc4a16e639409d938a4883…
- github.com/langflow-ai/langflow/pull/12290
- github.com/langflow-ai/langflow/security/advisories/GHSA-7w94-7…
- github.com/langflow-ai/langflow/security/advisories/GHSA-w794-r…
- github.com/langflow-ai/langflow/security/advisories/GHSA-7w94-7…
- github.com/langflow-ai/langflow/security/advisories/GHSA-w794-r…
Metrics
- CVSS 3.1
-
9.9
CRITICAL
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H - EPSS — exploit probability
- 4% percentile: 90 · as of 10 November 2026
- CWE
- CWE-78
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.