CVE-2026-35386
OpenSSH: OpenSSH: Arbitrary command execution via shell metacharacters in username
Severity
LowRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · April 3, 2026
Updated · October 2, 2026
Description
A flaw was found in OpenSSH. This vulnerability allows a remote attacker to achieve arbitrary command execution by injecting shell metacharacters into a username provided on the command line. Exploitation requires an untrusted username and a non-default configuration of the '%' character in ssh_config.
Statement
Red Hat products do not ship in a configuration which is subject to this vulnerability. Additionally, the impact of the command execution is limited to the scope of the specific user account which users would need to create themselves.
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
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
CVSS / CWE
CVSS 3.1 · 3.6CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N
CWE-78 · Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')