basic-ftp is an FTP client for Node.js. Prior to 5.3.1, basic-ftp is vulnerable to client-side denial of service when parsing FTP control-channel multiline responses. A malicious or compromised FTP server can send an unterminated multiline response during the initial FTP banner phase, before authentication. The client keeps appending attacker-controlled data into FtpContext._partialResponse and repeatedly reparses the accumulated buffer without enforcing a maximum control response size. As a result, an application using basic-ftp can remain stuck in connect() while memory and CPU usage grow under attacker-controlled input. This can lead to process-level denial of service, container OOM kills, worker restarts, queue backlog, or service degradation in applications that automatically connect to FTP endpoints. This vulnerability is fixed in 5.3.1.
History

Wed, 13 May 2026 00:45:00 +0000

Type Values Removed Values Added
First Time appeared Patrickjuchli
Patrickjuchli basic-ftp
Vendors & Products Patrickjuchli
Patrickjuchli basic-ftp

Tue, 12 May 2026 21:00:00 +0000

Type Values Removed Values Added
Description basic-ftp is an FTP client for Node.js. Prior to 5.3.1, basic-ftp is vulnerable to client-side denial of service when parsing FTP control-channel multiline responses. A malicious or compromised FTP server can send an unterminated multiline response during the initial FTP banner phase, before authentication. The client keeps appending attacker-controlled data into FtpContext._partialResponse and repeatedly reparses the accumulated buffer without enforcing a maximum control response size. As a result, an application using basic-ftp can remain stuck in connect() while memory and CPU usage grow under attacker-controlled input. This can lead to process-level denial of service, container OOM kills, worker restarts, queue backlog, or service degradation in applications that automatically connect to FTP endpoints. This vulnerability is fixed in 5.3.1.
Title basic-ftp allows a malicious FTP server to cause client-side denial of service via unbounded multiline control response buffering
Weaknesses CWE-400
CWE-770
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-05-12T20:37:43.098Z

Reserved: 2026-05-05T15:42:40.519Z

Link: CVE-2026-44240

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-05-12T21:16:16.410

Modified: 2026-05-12T21:16:16.410

Link: CVE-2026-44240

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-05-13T00:30:28Z