geldata gel-mcp server.py fetch_rule path traversal

A security flaw has been discovered in geldata gel-mcp 0.1.0. This impacts the function list_rules/fetch_rule of the file src/gel_mcp/server.py. The manipulation of the argument rule_name results in path traversal. The attack may be performed from remote. The exploit has been released to the public and may be used for attacks. The project was informed of the problem early through an issue report but has not responded yet.