Executive brief
A security vulnerability exists in the elinsky execution-system-mcp library, which is used to manage action lists and task contexts. An attacker can exploit this flaw to access or modify files on the server that should be restricted. This could lead to the unauthorized alteration of important documents or system files, potentially disrupting business workflows or compromising data integrity.
Technical details
A path traversal vulnerability (CWE-22) exists in elinsky execution-system-mcp 0.1.0 within the `add_action` tool and the `_get_context_file_path` function in `src/execution_system_mcp/server.py`. The application fails to sanitize the `context` and `file_path` arguments, allowing them to contain traversal sequences like `../../`. A remote attacker can provide a specially crafted string to escape the configured repository root and interact with arbitrary markdown files on the host filesystem that the service account has permissions to access. This allows for unauthorized reading and writing of files. While a proof-of-concept has been published, no official patch was available at the time of the report.
Affected products
- elinsky execution-system-mcp 0.1.0
Timeline
- 2026-04-10: disclosed: Vulnerability reported by independent researcher Winegee
- 2026-04-28: advisory: NVD/VulDB publication date