CVE-2026-85661: Haris-Musa Excel-Mcp-Server

Critical severity, CVSS 9.8. EPSS: 0.7% chance of exploitation in the next 30 days.

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.

Affected products

• Haris-Musa Excel-Mcp-Server: up to and including 0.1.8

Published 2026-09-04. Last modified 2026-09-23.