CVE-2026-85661

CRITICAL 9.8

excel-mcp-server 0.1.8 Arbitrary File Read/Write via stdio mode

CVSS Score

9.8

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-22
Vendor	haris-musa
Product	excel-mcp-server
Published	Sep 4, 2026
Last Updated	Sep 14, 2026

Stay Ahead of the Next One

Get instant alerts for haris-musa excel-mcp-server

Be the first to know when new critical vulnerabilities affecting haris-musa excel-mcp-server are published — delivered to Slack, Telegram or Discord.

Get Free Alerts → Free · No credit card · 60 sec setup

CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Affected Versions

haris-musa / excel-mcp-server

0 ≤ 0.1.8

References

NVD ↗ CVE.org ↗ EPSS Data ↗

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

Credits

George Chen