Vulnerability in Patrickjuchli Basic-Ftp
CVE-2026-39983
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.
Vulnerability class: CRLF Injection
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.6 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L.
EPSS exploit prediction
EPSS: 0.028 (85.9th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 86th percentile — 85.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.022 · newest: 0.028 · change: +0.006
Affected products
- Patrickjuchli Basic-Ftp — versions < 5.2.1
Weakness classification (CWE)
Public proof-of-concept exploits
References
- github.com/patrickjuchli/basic-ftp/security/advisories/GHSA-chqc-8p9q-pq6q (Exploit, Mitigation, Vendor Advisory)
- github.com/patrickjuchli/basic-ftp/commit/2ecc8e2c500c5234115f06fd1dbde1aa03d70… (Patch)
- github.com/patrickjuchli/basic-ftp/releases/tag/v5.2.1 (Product, Release Notes)
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
Frequently asked questions
- What is CVE-2026-39983?
- CVE-2026-39983 is a high-severity vulnerability in Patrickjuchli Basic-Ftp, classified under CRLF Injection. CVSS score: 8.6/10. Published 2026-04-09.
- How severe is CVE-2026-39983?
- High severity. CVSS v3 base score is 8.6 out of 10.
- Is CVE-2026-39983 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.