CVE-2026-85661

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 v3 9.8 CRITICAL

9.8^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 3.9 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
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

Configurations

No configuration.

History

No history.

Information

Published : 2026-09-04 15:17

Updated : 2026-09-14 20:16

NVD link : CVE-2026-85661

Mitre link : CVE-2026-85661

CVE.ORG link : CVE-2026-85661

JSON object : View

Products Affected

No product.

CWE

CWE-22

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

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