Local command execution via late username validation
Published Apr 2, 2026 · Updated Apr 2, 2026
Command injection in OpenSSH before 10.3 allows local users to execute commands via shell metacharacters in an untrusted username. The ssh client validates username shell metacharacters only after expanding percent tokens from ssh_config, allowing an unsafe value to reach Match exec. Exploitation requires an attacker-controlled username on the ssh command line and a non-default configuration such as %u in Match exec; commands run with the invoking user's privileges.
Summary
What happened
Command injection in OpenSSH before 10.3 allows local users to execute commands via shell metacharacters in an untrusted username. The ssh client validates username shell metacharacters only after expanding percent tokens from ssh_config, allowing an unsafe value to reach Match exec. Exploitation requires an attacker-controlled username on the ssh command line and a non-default configuration such as %u in Match exec; commands run with the invoking user's privileges.
The record
- CVE
- CVE-2026-35386
- Published
- Apr 2, 2026
- Updated
- Apr 2, 2026
- Vendor
- OpenBSD Project
- Product
- OpenSSH
- Classifications
- CWE-696, T1059
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Apr 2, 2026CVE publishedPublication date reported by the CVE source.
- Apr 2, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <10.3
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo