CVE-2026-39983 HIGH

CVE-2026-39983: FTP Command Injection via CRLF in basic-ftp

Vendor Patrickjuchli
Product basic-ftp
Weakness CWE-93 · CRLF injection
Published April 9, 2026
Last update June 30, 2026

CVSS base score

8.6/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality Low
Integrity High

CVSS vector

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

What the vulnerability does

01Description

basic-ftp is an FTP client for Node.js. Prior to 5.2.1, basic-ftp allows FTP command injection via CRLF sequences (\r\n) in file path parameters passed to high-level path APIs such as cd(), remove(), rename(), uploadFrom(), downloadTo(), list(), and removeDir(). The library's protectWhitespace() helper only handles leading spaces and returns other paths unchanged, while FtpContext.send() writes the resulting command string directly to the control socket with \r\n appended. This lets attacker-controlled path strings split one intended FTP command into multiple commands. This vulnerability is fixed in 5.2.1.

Key dates

02Disclosure timeline

April 9, 2026 CVE published
June 30, 2026 Record updated