PT-2026-33225 · Unknown · Excel-Mcp-Server
Published
2026-04-14
·
Updated
2026-04-21
·
CVE-2026-40576
CVSS v3.1
9.4
Critical
| Vector | AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:H |
Name of the Vulnerable Software and Affected Versions
excel-mcp-server versions prior to 0.1.8
Description
A path traversal issue exists in excel-mcp-server when operating in SSE or Streamable-HTTP transport modes. An unauthenticated network attacker can read, write, and overwrite arbitrary files on the host filesystem by providing crafted
filepath arguments to any of the 25 exposed MCP tool handlers. The issue stems from the get excel path() function, which fails to properly confine file operations to the directory specified by the EXCEL FILES PATH environment variable. Specifically, the function allows absolute paths to bypass the sandbox entirely and fails to resolve or validate relative paths, allowing the use of ../ sequences to escape the intended directory. This is further exacerbated by the server binding to 0.0.0.0 by default and requiring no authentication for network-facing transports.Recommendations
Update to version 0.1.8.
As a temporary workaround, restrict access to the network port used by the server or change the
FASTMCP HOST environment variable from 0.0.0.0 to a more secure address to limit network exposure.Exploit
Fix
RCE
Path traversal
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Weakness Enumeration
Related Identifiers
Affected Products
Excel-Mcp-Server