Cloudanix VulnDB

GHSA-j98m-w3xp-9f56

Critical · 9.4

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') in excel-mcp-server

CVSS

9.4

EPSS

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Published

Apr 14, 2026

CISA due date

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The record

A path traversal vulnerability exists in [`excel-mcp-server`](https://github.com/haris-musa/excel-mcp-server) versions up to and including `0.1.7`. When running in SSE or Streamable-HTTP transport mode (the documented way to use this server remotely), an unauthenticated attacker on the network can read, write, and overwrite arbitrary files on the host filesystem by supplying crafted `filepath` arguments to any of the 25 exposed MCP tool handlers. The server is intended to confine file operations to a directory set by the `EXCEL_FILES_PATH` environment variable. The function responsible for enforcing this boundary — `get_excel_path()` — fails to do so due to two independent flaws: it passes absolute paths through without any check, and it joins relative paths without resolving or validating the result. Combined with zero authentication on the default network-facing transport and a default bind address of `0.0.0.0` (all interfaces), this allows trivial remote exploitation. ---

Affected packages

Ecosystem Package Introduced Fixed

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