CVE-2026-44240

CVE-2026-44240 · basic-ftp allows a malicious FTP server to cause client-side denial of service via unbounded multiline control response buffering

This page contains facts from public vulnerability sources. Check the original advisory before updating.

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.

CVSS 7.5 · High · EPSS 0.5% · Fix available

Published

2026-05-12T20:37:43.098Z

Updated

2026-05-14T12:31:57.807Z

Stack: system · node

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