Improper Check or Handling of Exceptional Conditions in libssh - CVE-2026-59845
Published: July 27, 2026
Vulnerability identifier: #VU139524
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/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-2026-59845
CWE-ID: CWE-703
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: libssh
Affected software:
libssh
libssh
Detailed vulnerability description
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to improper handling of fork() failure in ProxyCommand execution in the libssh client when cleaning up a session after executing a ProxyCommand. A local user can trigger a fork() failure and then cause the process to send a KILL signal to process group -1 to cause a denial of service.
This issue affects the client only and typically occurs under low-memory conditions.
How to mitigate CVE-2026-59845
Install security update from vendor's website.