CVE-2026-39983

HIGH

FTP Command Injection via CRLF in basic-ftp

Title source: cna
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2026-39983. PoCs published by zebbernCVE.

AI-analyzed exploit summary This repository provides references to the advisory, patch commit, and release for CVE-2026-39983 in the basic-ftp library. It does not contain exploit code but links to technical details and fixes.

Description

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.

Exploits (1)

nomisec WRITEUP
by zebbernCVE · poc
https://github.com/zebbernCVE/CVE-2026-39983

This repository provides references to the advisory, patch commit, and release for CVE-2026-39983 in the basic-ftp library. It does not contain exploit code but links to technical details and fixes.

Classification
Writeup 90%
Attack Type
Other
Complexity
N/a
Reliability
N/a
Target: basic-ftp v5.2.1
No auth needed
devstral-2 · analyzed Apr 11, 2026 Full analysis →

Scores

CVSS v3 8.6
EPSS 0.0204
EPSS Percentile 84.3%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L

CISA SSVC

Vulnrichment
Exploitation poc
Automatable yes
Technical Impact partial

Details

CWE
CWE-93
Status published
Products (2)
npm/basic-ftp 5.2.0 - 5.2.1npm
patrickjuchli/basic-ftp < 5.2.1 (2 CPE variants)
Published Apr 09, 2026
Tracked Since Apr 09, 2026