This vulnerability in geldata gel-mcp 0.1.0 arises from improper validation of the rule_name parameter in the list_rules/fetch_rule function within src/gel_mcp/server.py. An attacker can manipulate this argument to perform path traversal attacks, potentially accessing unauthorized files on the server. The vulnerability is remotely exploitable without authentication or user interaction. Despite early notification, the vendor has not provided a patch or official remediation guidance. The CVSS 4.0 score of 6.9 reflects a medium severity level due to network attack vector, low complexity, and no privileges required.

Successful exploitation could allow an attacker to read arbitrary files on the affected system by traversing directories via the rule_name parameter. This could lead to disclosure of sensitive information stored on the server. There is no indication of privilege escalation, denial of service, or code execution from the available data. No confirmed exploitation in the wild has been reported yet.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Since the vendor has not responded or issued a fix, users should consider implementing temporary mitigations such as restricting network access to the affected service, applying input validation or filtering on the rule_name parameter if possible, and monitoring for suspicious activity related to this function. Avoid exposing the vulnerable service to untrusted networks until a patch is available.