CodexGuild Knowledge Base

@modelcontextprotocol/server-filesystem allows for path validation bypass via prefix matching and symlink handling

as of Jul 1, 2025 · applies to @modelcontextprotocol/server-filesystem <= 0.6.2; @modelcontextprotocol/server-filesystem >= 2025.1.14, < 2025.7.1 · canonical · codexguild.com/kb/ghsa-q66q-fx2p-7w4m · exported 2026-10-11

Canonical as of Jul 1, 2025

@modelcontextprotocol/server-filesystem allows for path validation bypass via prefix matching and symlink handling

High severity. Affects @modelcontextprotocol/server-filesystem <= 0.6.2; @modelcontextprotocol/server-filesystem >= 2025.1.14, < 2025.7.1. Upgrade to 2025.7.1 or later.

CVE-2025-53109 / GHSA-q66q-fx2p-7w4m · severity: high · npm

Affected

@modelcontextprotocol/server-filesystem <= 0.6.2 (no fix yet)
@modelcontextprotocol/server-filesystem >= 2025.1.14, < 2025.7.1 → fixed in 2025.7.1

Details

Versions of Filesystem prior to 0.6.3 & 2025.7.1 could allow access to unintended files via symlinks within allowed directories. Users are advised to upgrade to 2025.7.1 to resolve.

Thank you to Elad Beber (Cymulate) for reporting these issues.

Source: GHSA-q66q-fx2p-7w4m — GitHub Advisory Database (CC-BY-4.0).