Executive brief
A vulnerability exists in the n8n-workflow-builder tool, which is used to integrate AI assistants with n8n automation workflows. An attacker with local access can trick the tool into reading sensitive files from the host computer and saving their contents into an n8n workflow. This could lead to the exposure of private configuration files, credentials, or other sensitive data stored on the system.
Technical details
A path traversal vulnerability exists in the 'update_node_from_file' tool within the makafeli n8n-workflow-builder MCP server (up to version 0.11.0). The 'filePath' argument in 'build/server.cjs' is passed directly to 'fs.readFileSync' without adequate validation or workspace boundary checks. A local attacker, or an AI agent influenced by malicious prompts, can provide an absolute path to sensitive files. The server reads the file content and persists it into a target n8n workflow node parameter via the n8n API, where it can then be retrieved by the attacker. As of the advisory date, the project has not responded to the issue report.
Affected products
- makafeli n8n-workflow-builder up to 0.11.0
Timeline
- 2026-07-12: disclosed: Issue reported to the maintainer via GitHub issue #28
- 2026-07-13: advisory: CVE published to NVD dataset