dbcve.org
Basic FtpApplication · Patrickjuchli

CVE-2026-27699

CRITICAL · 9.8 CVSS v3.1 Published 2026-02-25
Fix available
A fix is available. Upgrade to 5.2.0 or later.
See remediation →
100/100
Remediation priority · Urgent
Public exploit Remotely reachable No privileges Zero-click Patch available

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
The `basic-ftp` FTP client library for Node.js contains a path traversal vulnerability (CWE-22) in versions prior to 5.2.0 in the `downloadToDir()` method. A malicious FTP server can send directory listings with filenames containing path traversal sequences (`../`) that cause files to be written outside the intended download directory. Version 5.2.0 patches the issue.

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 · high confidence

The basic-ftp library for Node.js versions prior to 5.2.0 contain a path traversal vulnerability (CWE-22) in the downloadToDir() method. A malicious or compromised FTP server can send directory listings containing '../' sequences in filenames, causing the client to write files outside the intended download directory, potentially overwriting system files or exposing sensitive data.

MitigationUpgrade the basic-ftp package to version 5.2.0 or later to apply the patch that addresses this path traversal vulnerability.

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

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Basic FtpApplication
Affected:< 5.2.0

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
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

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

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. Identify if basic-ftp is installed
    Check your project's package.json file under dependencies or devDependencies for 'basic-ftp' or examine node_modules for the basic-ftp package directory
    Affected if The package is listed in dependencies and was installed (check node_modules/basic-ftp/package.json for version)
  2. Determine the installed version
    Run 'npm list basic-ftp' or inspect node_modules/basic-ftp/package.json to read the 'version' field
    Affected if The version number is less than 5.2.0 (e.g., 5.1.0, 5.0.0, etc.)
  3. Check for usage of downloadToDir method
    Search your codebase for calls to downloadToDir (e.g., grep -r 'downloadToDir' or search in your IDE)
    Affected if Your code calls the downloadToDir method to download files from FTP servers
  4. Verify download directory configuration
    Review the directory path passed as the first argument to downloadToDir in your code
    Affected if The method is used with a download directory path (this is required for the vulnerability to be exploitable)
  5. Inspect application logs for path anomalies
    Search server or application logs for file paths containing '../' or '..\' patterns in download operations
    Affected if Logs show file writes occurring outside the intended download directory (evidence of exploitation)

You are affected if basic-ftp version less than 5.2.0 is installed AND your application uses the downloadToDir method to fetch files from FTP servers.

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.

dbcve · scoped
Upgrade available Upgrade to 5.2.0 or later
Fixed in 5.2.0
Vendor patch github.com →
Interim mitigation

Upgrade the basic-ftp package to version 5.2.0 or later to apply the patch that addresses this path traversal vulnerability.

Recommended fix High confidence

basic-ftp version 5.2.0 or higher

  1. 1. Identify all projects that depend on the `basic-ftp` package by checking package.json files or lock files
  2. 2. Run `npm list basic-ftp` or `yarn list basic-ftp` in each project to check the currently installed version
  3. 3. If the installed version is below 5.2.0, upgrade by running `npm install basic-ftp@^5.2.0` or `yarn add basic-ftp@^5.2.0`
  4. 4. Verify the upgrade was successful by running the package manager list command again
  5. 5. Run your project's test suite to ensure the upgrade does not break existing functionality
  6. 6. Rebuild and redeploy any applications using this library
Caveat Review the basic-ftp changelog between your current version and 5.2.0 for any breaking changes in the API

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Basic Ftp Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing3.0 h
  • Review / QA2.0 h
8.0 hours of engineering $1,390
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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-2026-27699 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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