CVE-2026-39983

CVE-2026-39983 is a high-severity vulnerability in Patrickjuchli Basic-ftp with a CVSS 3.x base score of 8.6. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-93.

Key facts

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.

Frequently asked questions

What is 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.
How severe is CVE-2026-39983?
CVE-2026-39983 has a CVSS 3.x base score of 8.6, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity high, and availability low.
Is CVE-2026-39983 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (80th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-39983?
CVE-2026-39983 affects Patrickjuchli Basic-ftp. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-39983?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-39983 have an EU (EUVD) identifier?
Yes. CVE-2026-39983 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-20976.
When was CVE-2026-39983 published?
CVE-2026-39983 was published on 2026-04-09 and last updated on 2026-06-30.

References

Affected products (1)

More vulnerabilities in Patrickjuchli Basic-ftp

All CVEs affecting Patrickjuchli Basic-ftp →

Other CWE-93 (CRLF Injection) vulnerabilities

Browse all CWE-93 (CRLF Injection) vulnerabilities →