What’s Vulnerable › Vulnerabilities

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

• Severity: high (CVSS 8.6 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 2.2% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-04-09 · updated 2026-10-26
• Weakness: CWE-93

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.

Affected products

• patrickjuchli basic-ftp: before 5.2.1 — fixed in 5.2.1

How to fix

Upgrade to a fixed version: patrickjuchli basic-ftp 5.2.1. Check the vendor advisory for mitigations.

References

• https://github.com/patrickjuchli/basic-ftp/commit/2ecc8e2c500c5234115f06fd1dbde1aa03d70f4b
• https://github.com/patrickjuchli/basic-ftp/releases/tag/v5.2.1
• https://github.com/patrickjuchli/basic-ftp/security/advisories/GHSA-chqc-8p9q-pq6q
• https://access.redhat.com/errata/RHSA-2026:13826
• https://access.redhat.com/errata/RHSA-2026:9742
• https://access.redhat.com/security/cve/CVE-2026-39983
• https://bugzilla.redhat.com/show_bug.cgi?id=2456971
• https://github.com/patrickjuchli/basic-ftp/security/advisories/GHSA-chqc-8p9q-pq6q
• https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-39983.json

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