dbcve.org
InjectionWeakness · CWE-74

CVE-2026-5327

MEDIUM · 6.3 CVSS v3.1 Published 2026-04-02
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
69/100
Remediation priority · Elevated
Remotely reachable Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A security flaw has been discovered in efforthye fast-filesystem-mcp up to 3.5.1. The affected element is the function handleGetDiskUsage of the file src/index.ts. Performing a manipulation results in command injection. The attack is possible to be carried out remotely. The exploit has been released to the public and may be used for attacks. The project was informed of the problem early through an issue report but has not responded yet.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

The handleGetDiskUsage function in src/index.ts of the efforthye fast-filesystem-mcp package (versions up to 3.5.1) is vulnerable to command injection. Attackers can manipulate input to the function to execute arbitrary system commands remotely. This affects a filesystem utility used for disk usage monitoring.

MitigationUntil an official patch is released, ensure the handleGetDiskUsage function is not exposed to untrusted input, and implement strict input validation/sanitization to prevent shell metacharacter injection. Consider restricting network access to any APIs exposing this functionality.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
Low

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check if fast-filesystem-mcp package is installed
    Run 'npm list fast-filesystem-mcp' or check your package.json dependencies for 'efforthye/fast-filesystem-mcp' or 'fast-filesystem-mcp'
    Affected if The package is listed in dependencies
  2. Verify the installed version
    Run 'npm list fast-filesystem-mcp' to see the installed version, or check the version field in node_modules/fast-filesystem-mcp/package.json
    Affected if Version is 3.5.1 or lower
  3. Inspect the source code for handleGetDiskUsage usage
    Search for 'handleGetDiskUsage' in your codebase or in node_modules/fast-filesystem-mcp/src/index.ts to confirm the vulnerable function exists in your deployment
    Affected if The function is present in the installed package version
  4. Determine if the function is exposed to network or API callers
    Review your application code to see if handleGetDiskUsage is bound to any API endpoint, RPC handler, or other network-accessible interface
    Affected if The function is exposed via an API, endpoint, or any external interface
  5. Check if untrusted input reaches the function
    Review the code path from external input (request parameters, user-provided paths, query arguments) to the handleGetDiskUsage call to see if input is passed without sanitization
    Affected if User-controlled or external input can reach handleGetDiskUsage without validation

You are affected if fast-filesystem-mcp version 3.5.1 or lower is installed AND the handleGetDiskUsage function is exposed to untrusted input that could contain shell metacharacters.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Until an official patch is released, ensure the handleGetDiskUsage function is not exposed to untrusted input, and implement strict input validation/sanitization to prevent shell metacharacter injection. Consider restricting network access to any APIs exposing this functionality.

Have this fixed Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,130
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-5327 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
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  • Version or environment caveats, and links to real fixes
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