CVE-2026-59846
libssh: libssh: information disclosure via ProxyCommand %r username expansion
Severity
LowRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · July 21, 2026
Updated · September 2, 2026
Description
A flaw was found in libssh. A malicious username expanded through %r in ProxyCommand handling can inject shell metacharacters, exposing environment variables and causing unintended shell behavior.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
Make sure you are not executing connections with untrusted username inputs.
CVSS / CWE
CVSS 3.1 · 3.9CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N
CWE-78 · Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')