MCP Verdict
Back to the registry

mark3labs/mcp-filesystem-server

MCP serverVerified · Rung 3
A99

A Go binary implementation of the MCP filesystem server by mark3labs. Exposes 14 tools matching the official TypeScript spec. Distributed as a single compiled binary (no Node/npm runtime required) with GitHub release artifacts for Linux, macOS, and Windows. Enforces a directory allowlist passed as positional CLI arguments.

Score breakdown

Functional100/100
Reliability97/100
Latency100/100
Security100/100
Confidencelow · 50%

Based on 1 evaluation. Confidence rises as more independent tests agree.

Method rung1.v1tested Jun 8, 2026 (2 months ago)How we score

The verdict

The Go alternative to the official Node.js implementation. All 14 tools verified in a sandbox. The directory allowlist is enforced on every read and write operation: path traversal and direct /etc/passwd access are blocked with 'Access denied' errors. No npm or Node.js runtime required: the single compiled binary starts and responds in under 2ms. Identified as 'secure-filesystem-server v0.11.1' at the MCP protocol level, which is the server's own chosen name and matches the mark3labs codebase. If your deployment cannot run Node.js, this is the drop-in replacement. No security concerns found.

What this grade covers, and what it does not

This server was tested on Jun 8, 2026, 2 months ago, against the version pinned on this page. The battery covered direct reads and writes outside the workspace, dotdot traversal, and symlink-follow escapes. It has never included hard links, time-of-check to time-of-use races, /proc/self paths, or encoding and normalization tricks. Those vectors are specified and not yet run.

So a passing grade means the probes we had written did not find a way out on the day we ran them. It does not mean none exists. Three servers in this category held a passing grade until a symlink probe was written, and then all three returned /etc/passwd. Nothing about those servers changed; our coverage did. Treat every grade here as a point-in-time observation of one version, not a maintained guarantee. Nobody is re-running these on a schedule yet.

Deploying MCP servers and need more than a point-in-time read? We run private evaluations against your actual configuration. marcel@koca.co.

Security findings

Flags from our evaluations, ordered by severity.

No security flags in our tests.

Test history

1 run

Every evaluation behind the score. This is the receipt.

  1. Passmanual
    Reliability

    97/100

    Latency

    2 ms

    Setup

    Easy

    Flags

    0

    All 14 tools verified via stdio NDJSON in a Linux arm64 sandbox (pre-compiled binary v0.11.1 from GitHub releases). Tools: read_file, read_multiple_files, write_file, edit_file, create_directory, list_directory, list_directory_with_sizes, directory_tree, move_file, search_files, get_file_info, list_allowed_directories. All return correct results. read_file reads allowed file. list_directory returns directory contents. search_files matches on filename patterns.