Input validation error in libssh - CVE-2026-59844
Published: July 27, 2026
Vulnerability identifier: #VU139527
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-59844
CWE-ID: CWE-20
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: libssh
Affected software:
libssh
libssh
Detailed vulnerability description
The vulnerability allows a remote user to cause a denial of service.
The vulnerability exists due to improper input validation in the libssh SFTP server when processing SSH_FXP_READ requests. A remote user can send a specially crafted SSH_FXP_READ request with an excessive read length value to cause a denial of service.
The issue can be sustained by repeatedly issuing large read requests simultaneously over multiple SFTP channels.
How to mitigate CVE-2026-59844
Install security update from vendor's website.