CVE-2026-39983: CWE-93: Improper Neutralization of CRLF Sequences ('CRLF Injection') in patrickjuchli basic-ftp
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.
AI Analysis
Technical Summary
CVE-2026-39983 is a CRLF injection vulnerability in the basic-ftp Node.js client before version 5.2.1. The issue arises because the protectWhitespace() helper only handles leading spaces and leaves other path characters unchanged. When path parameters containing CRLF sequences are passed to high-level APIs such as cd(), remove(), rename(), uploadFrom(), downloadTo(), list(), and removeDir(), the resulting FTP command string sent via FtpContext.send() can be split into multiple commands. This improper neutralization of CRLF sequences (CWE-93) allows FTP command injection. The vulnerability is resolved in version 5.2.1.
Potential Impact
An attacker can inject additional FTP commands by including CRLF sequences in file path parameters, potentially leading to unauthorized command execution on the FTP server. The CVSS 3.1 score is 8.6 (high severity) with network attack vector, low attack complexity, no privileges or user interaction required, and impacts confidentiality, integrity, and availability to varying degrees.
Mitigation Recommendations
A fix is available in basic-ftp version 5.2.1. Users should upgrade to version 5.2.1 or later to remediate this vulnerability. Refer to the Red Hat advisories for additional vendor-specific guidance and patches.
CVE-2026-39983: CWE-93: Improper Neutralization of CRLF Sequences ('CRLF Injection') in patrickjuchli basic-ftp
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.
CVSS v3.1
Score 8.6high
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-39983 is a CRLF injection vulnerability in the basic-ftp Node.js client before version 5.2.1. The issue arises because the protectWhitespace() helper only handles leading spaces and leaves other path characters unchanged. When path parameters containing CRLF sequences are passed to high-level APIs such as cd(), remove(), rename(), uploadFrom(), downloadTo(), list(), and removeDir(), the resulting FTP command string sent via FtpContext.send() can be split into multiple commands. This improper neutralization of CRLF sequences (CWE-93) allows FTP command injection. The vulnerability is resolved in version 5.2.1.
Potential Impact
An attacker can inject additional FTP commands by including CRLF sequences in file path parameters, potentially leading to unauthorized command execution on the FTP server. The CVSS 3.1 score is 8.6 (high severity) with network attack vector, low attack complexity, no privileges or user interaction required, and impacts confidentiality, integrity, and availability to varying degrees.
Mitigation Recommendations
A fix is available in basic-ftp version 5.2.1. Users should upgrade to version 5.2.1 or later to remediate this vulnerability. Refer to the Red Hat advisories for additional vendor-specific guidance and patches.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-04-08T00:01:47.628Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
- Vendor Advisory Urls
- [{"url":"https://access.redhat.com/security/cve/CVE-2026-39983","vendor":"Red Hat"},{"url":"https://access.redhat.com/errata/RHSA-2026:9742","vendor":"Red Hat"},{"url":"https://access.redhat.com/errata/RHSA-2026:13826","vendor":"Red Hat"}]
Threat ID: 69d806d51cc7ad14da15a66c
Added to database: 04/09/2026, 20:06:45 UTC
Last enriched: 07/15/2026, 09:06:16 UTC
Last updated: 07/31/2026, 19:22:58 UTC
Views: 219
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