CVE-2026-40576

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.

• CWE-22

• https://github.com/haris-musa/excel-mcp-server/security/advisories/GHSA-j98m-w3xp-9f56
• https://github.com/haris-musa/excel-mcp-server/security/advisories/GHSA-j98m-w3xp-9f56

Published

Apr 21, 2026

Last Modified

Jun 17, 2026

Status

Deferred

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
• Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
• PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
• AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.

• CVE-2026-4057The Download Manager plugin for WordPress is vulnerable to u…4.3
• CVE-2026-40570FreeScout is a free self-hosted help desk and shared mailbox…5.7
• CVE-2026-40571NamelessMC is website software for Minecraft servers. In ver…5.3
• CVE-2026-40572NovumOS is a custom 32-bit operating system written in Zig a…9
• CVE-2026-40574OAuth2 Proxy is a reverse proxy that provides authentication…6.8
• CVE-2026-40575OAuth2 Proxy is a reverse proxy that provides authentication…9.1
• CVE-2026-4058The User Frontend: AI Powered Frontend Posting, User Directo…4.3
• CVE-2026-40581ChurchCRM is an open-source church management system. In ver…8.1
• CVE-2026-40582ChurchCRM is an open-source church management system. In ver…9.1
• CVE-2026-40583UltraDAG is a minimal DAG-BFT blockchain in Rust. In version…8.2
• CVE-2026-40584RansomLook is a tool to monitor Ransomware groups and market…7.5
• CVE-2026-40585blueprintUE is a tool to help Unreal Engine developers. Prio…7.4