Out-of-bounds read in WS_FTP - CVE-2026-90869
Published: October 29, 2026
Vulnerability identifier: #VU158502
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-90869
CWE-ID: CWE-125
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service in the SSH service.
The vulnerability exists due to an out-of-bounds read in the SSH authentication functionality of Progress WS_FTP Server when processing malformed public-key signatures before authentication. A remote attacker can send specially crafted authentication data to disrupt the SSH service.
Affected software
WS_FTP
How to mitigate CVE-2026-90869
Install security update from vendor's website.
WS_FTP - addressed in versions 9.0.7, 10.0.4