CVE-2026-85661

CVSS 9.8 (critical) · published 2026-09-04

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.

Weakness: CWE-22

Source: NVD CVE-2026-85661

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.py
• https://github.com/haris-musa/excel-mcp-server/blob/v0.1.8/src/excel_mcp/validation.py
• https://github.com/haris-musa/excel-mcp-server/issues/149
• https://www.vulncheck.com/advisories/excel-mcp-server-0.1.8-arbitrary-file-read-write-via-stdio-mode

Check your software

Connect an AI agent to the FixLane MCP server or ask the Telegram bot to check what you have installed against incidents with a verified fixed version.