CVE-2026-69263

Name of the Vulnerable Software and Affected Versions Flowise versions prior to 3.1.3

Description An incomplete environment variable validation in the validateEnvironmentVariables() function within packages/components/nodes/tools/MCP/core.ts allows a bypass of security controls intended to prevent the auto-installation of arbitrary packages. While the software blocks the -y and --yes flags for npx, it only denies a limited set of environment variables (PATH, LD LIBRARY PATH, DYLD LIBRARY PATH, and NODE OPTIONS) by exact name. An attacker can use the npm config yes variable set to true to reproduce the --yes behavior, causing npx to automatically install and execute a specified package. This can lead to unauthenticated remote code execution on default deployments. Other variables such as npm config prefix, npm config userconfig, NODE PATH, PYTHONPATH, and PYTHONSTARTUP can also be used to influence execution through permitted interpreters.

Recommendations Update Flowise to version 3.1.3. As a temporary mitigation, restrict the use of the env object in MCP server configurations or avoid using the npm config yes variable.