Vulnerability Description
excel-mcp-server 0.1.8 fails to enforce path confinement in stdio mode when EXCEL_FILES_PATH is unset, allowing attackers to read and write arbitrary files. Attackers can supply unchecked file paths to read and write tools to access any file accessible to the process.
CVSS Score
CRITICAL
Related Weaknesses (CWE)
References
- https://github.com/haris-musa/excel-mcp-server
- https://github.com/haris-musa/excel-mcp-server/blob/v0.1.8/src/excel_mcp/server.
- https://github.com/haris-musa/excel-mcp-server/blob/v0.1.8/src/excel_mcp/validat
- https://github.com/haris-musa/excel-mcp-server/issues/149
- https://www.vulncheck.com/advisories/excel-mcp-server-0.1.8-arbitrary-file-read-
FAQ
What is CVE-2026-85661?
CVE-2026-85661 is a vulnerability with a CVSS score of 9.8 (CRITICAL). excel-mcp-server 0.1.8 fails to enforce path confinement in stdio mode when EXCEL_FILES_PATH is unset, allowing attackers to read and write arbitrary files. Attackers can supply unchecked file paths t...
How severe is CVE-2026-85661?
CVE-2026-85661 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-85661?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.