Description
basic-ftp is an FTP client for Node.js. Prior to 6.2.4, the MLSD directory-listing parser in src/parseListMLSD.ts uses untrusted fact names from the FTP server as keys in the plain-object factHandlersByName dictionary without checking that the resolved property is an own handler. A fact named __proto__ therefore resolves to Object.prototype, bypasses the missing-handler guard, and is called as though it were a function, producing a TypeError. The error propagates through Client.list() and APIs that depend on it because it is not an FTPError. A malicious or compromised FTP server, or an on-path attacker on a plaintext FTP session, can make the affected operation reject, and the Node.js process terminates under the default behavior in Node.js 15 and later only if the application leaves that rejection unhandled. This issue is fixed in version 6.2.4.
Published: 2026-11-12
Score: 5.3 Medium
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories
Source ID Title
Github GHSA Github GHSA GHSA-5pm8-86m8-9m6r basic-ftp: Uncaught TypeError in MLSD directory-listing parser via __proto__ fact name causes DoS in Client.list()
History

Thu, 12 Nov 2026 21:45:00 +0000

Type Values Removed Values Added
Description basic-ftp is an FTP client for Node.js. Prior to 6.2.4, the MLSD directory-listing parser in src/parseListMLSD.ts uses untrusted fact names from the FTP server as keys in the plain-object factHandlersByName dictionary without checking that the resolved property is an own handler. A fact named __proto__ therefore resolves to Object.prototype, bypasses the missing-handler guard, and is called as though it were a function, producing a TypeError. The error propagates through Client.list() and APIs that depend on it because it is not an FTPError. A malicious or compromised FTP server, or an on-path attacker on a plaintext FTP session, can make the affected operation reject, and the Node.js process terminates under the default behavior in Node.js 15 and later only if the application leaves that rejection unhandled. This issue is fixed in version 6.2.4.
Title basic-ftp: Uncaught TypeError in MLSD directory-listing parser via __proto__ fact name causes DoS in Client.list()
Weaknesses CWE-1321
CWE-248
References
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'}


Subscriptions

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-11-12T21:29:44.321Z

Reserved: 2026-11-10T21:12:01.226Z

Link: CVE-2026-126345

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Deferred

Published: 2026-11-12T22:19:19.447

Modified: 2026-11-12T22:19:19.570

Link: CVE-2026-126345

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

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Weaknesses