Input validation error in OpenSSH - CVE-2026-35386
Published: April 29, 2026
Vulnerability identifier: #VU128473
CSH Severity: Low
CVSSv4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-35386
CWE-ID: CWE-20
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerable software:
OpenSSH
OpenSSH
Software vendor:
OpenSSH
OpenSSH
Description
The vulnerability allows a local user to execute arbitrary shell commands.
The vulnerability exists due to improper input validation in ssh(1) when expanding %-tokens from ssh_config using a user name supplied on the command-line. A local user can supply a specially crafted user name to execute arbitrary shell commands.
Exploitation requires a configuration that uses the %u token in a Match exec block.
Remediation
Install security update from vendor's website.