CVE-2026-105740: Authenticated RCE in Langflow 1.8.3

CVE-2026-105740 describes a Remote Code Execution (RCE) vulnerability in Langflow, a platform for building and deploying AI-powered agents and workflows. The flaw affects all versions prior to 1.9.0. Any authenticated user can achieve remote command execution by adding an MCP server with Stdio transport, without the system applying validation or sandboxing controls.

User-supplied commands are passed directly to bash -c "exec {command}" without checks and no allowlisting. Additionally, arbitrary environment variable injection is possible (LD_PRELOAD, PATH override). The CVSS score is 9.9 on critical scale. A fix is available in the official 1.9.0 release. Signals collected from X show active attention to the vulnerability with 4 posts in recent days.

System administrators and IT teams running Langflow in production must update immediately to version 1.9.0. Before the update, restrict access to the Langflow console to trusted users only and monitor logs for anomalous MCP server additions. Disable unauthorized remote access to the platform until patching is complete.