CVE-2026-40576: haris-musa excel-mcp-server · Path Traversal
Affects haris-musa excel-mcp-serverSource CVE Database V5
Not known to be exploited · CVSS 9.4 Critical : upgrade to 0.1.8 as a priority.
Data as of 29 Oct 2026, 19:04 UTC
Contested
Critical score, yet low EPSS after six months- EPSS
- 0.4% chance of exploitation in 30 days – higher than 40% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 0.1.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 21 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
Upgrade excel-mcp-server and haris-musa/excel-mcp-server to 0.1.8.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| haris-musaexcel-mcp-server | Affected
| Fixed in
|
GitHubharis-musa/excel-mcp-serverpkg:github/haris-musa/excel-mcp-serverOther threats | Affected
| Fixed in
|
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AI-suggested
A patch is available in excel-mcp-server version 0.1.8 that fixes the path traversal vulnerability. Users should upgrade to version 0.1.8 or later to remediate this issue. Since this is a cloud service, the vendor manages remediation for the hosted service; users should verify with the vendor that the service is updated. Until patched, restricting network access to the server and avoiding use of the vulnerable transport modes can reduce exposure.
Description
excel-mcp-server is a Model Context Protocol server for Excel file manipulation. A path traversal vulnerability exists in 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. This vulnerability is fixed in 0.1.8.