CVE-2026-27699: Patrickjuchli Basic-FTP

Critical severity, CVSS 9.8. EPSS: 1% chance of exploitation in the next 30 days.

The `basic-ftp` FTP client library for Node.js contains a path traversal vulnerability (CWE-22) in versions prior to 5.2.0 in the `downloadToDir()` method. A malicious FTP server can send directory listings with filenames containing path traversal sequences (`../`) that cause files to be written outside the intended download directory. Version 5.2.0 patches the issue.

Affected products

• Patrickjuchli Basic-FTP: before 5.2.0 (fixed in 5.2.0)

Published 2026-02-25. Last modified 2026-06-17.