Path traversal in basic-ftp - CVE-2026-27699
Published: April 6, 2026
Vulnerability identifier: #VU124878
CSH Severity: High
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber
CVE-ID: CVE-2026-27699
CWE-ID: CWE-22
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: patrickjuchli
Affected software:
basic-ftp
basic-ftp
Detailed vulnerability description
The vulnerability allows a remote attacker to perform directory traversal attacks.
The vulnerability exists due to input validation error when processing directory traversal sequences in the `downloadToDir()` method. A remote attacker operating 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.
How to mitigate CVE-2026-27699
Install updates from vendor's website.