Use-after-free in libssh - CVE-2026-59850
Published: July 27, 2026
Vulnerability identifier: #VU139533
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-59850
CWE-ID: CWE-416
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 use-after-free in channel data callbacks when processing data on closed channels. A remote user can send data through a closed channel to cause a denial of service.
The issue affects both server and client components and is exemplified on SFTP channels.
How to mitigate CVE-2026-59850
Install security update from vendor's website.