The vulnerability resides in the MCP Gmail Tool’s saveToDisk function within the gmail.ts module. Improper access control allows an attacker to bypass intended safeguards and write files to arbitrary locations on disk. This access can be exploited remotely and the public exploit demonstrates that malicious code could be executed with elevated privileges. The flaw permits unauthorized disclosure and modification of data stored on the host system, compromising confidentiality and integrity of the local environment.

The affected product is j3k0 mcp-google-workspace, a rolling‑release tool for managing Google Workspace integration. Any instance built from a commit older than 89c091ecf8b9f9c7291d1af0b1966e271f86551c is vulnerable. No specific version ranges are available because the release model does not tag releases pre‑patch.

The CVSS score of 5.3 indicates moderate severity, but the lack of an EPSS score does not reflect the absence of exploitation attempts. The vulnerability is publicly available and can be triggered remotely, suggesting a realistic exploitation probability. The weakness is based on access‑control and privilege‑injection failures (CWE‑266, CWE‑284). Given its remote nature and the public exploit, the risk to environments running unpatched code is significant, especially where the tool has high privileges or unrestricted file access.