Path traversal in WS_FTP - CVE-2026-90871
Published: October 29, 2026
Vulnerability identifier: #VU158505
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-90871
CWE-ID: CWE-22
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to delete files outside the intended directory.
The vulnerability exists due to path traversal in the Ad Hoc Transfer and Web Transfer components of Progress WS_FTP Server when processing file deletion paths. A remote attacker can submit a crafted path under specific conditions to delete files outside the intended directory.
Affected software
WS_FTP
How to mitigate CVE-2026-90871
Install security update from vendor's website.
WS_FTP - addressed in versions 9.0.7, 10.0.4