OpenSSH agent forwarding path validation

What happened

The forwarding path is insufficiently constrained in a narrow agent-forwarding configuration. A remote actor with an existing authenticated path may influence how a local socket is resolved.

Affected versions

OpenSSH Agent: ≤ 9.9p1 Fixed: 10.0p1.

Why it matters

Agent forwarding often bridges trust boundaries. A validation failure can expose credentials or administrative workflows beyond the intended host.

Detection & mitigation

• Upgrade to OpenSSH 10.0p1 or later.
• Disable agent forwarding where it is not operationally required.
• Restrict forwarding to explicitly trusted hosts and review agent socket access.