CVE-2026-85756

SSH.NET: ScpClient allows server-side RCE via default SCP path handling

Published Sep 16, 2026 CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed
Description
SSH.NET is a Secure Shell (SSH) library for .NET. Prior to 2026.0.0, ScpClient places caller-supplied remote paths into the command used to run scp on the server, and the default RemotePathTransformation.DoubleQuote transformation cannot safely quote every remote command interpreter. When an application passes an attacker-controlled path to a shell-based server, shell metacharacters not neutralized by the active IRemotePathTransformation can execute commands as the authenticated SSH user. Exploitation requires a shell-based server and a path crafted for that shell's parsing rules; non-shell servers and paths fully neutralized by the selected transformation are not affected. RemotePathTransformation.ShellQuote is available for POSIX shells, while SftpClient avoids a remote shell entirely. This issue is fixed in version 2026.0.0.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-mggc-4xg6-vcxf SSH.NET: ScpClient allows server-side RCE via default SCP path handling
History
Type Values Removed Values Added
First Time appeared Sshnet
Sshnet ssh.net
Vendors & Products Sshnet
Sshnet ssh.net
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description SSH.NET is a Secure Shell (SSH) library for .NET. Prior to 2026.0.0, ScpClient places caller-supplied remote paths into the command used to run scp on the server, and the default RemotePathTransformation.DoubleQuote transformation cannot safely quote every remote command interpreter. When an application passes an attacker-controlled path to a shell-based server, shell metacharacters not neutralized by the active IRemotePathTransformation can execute commands as the authenticated SSH user. Exploitation requires a shell-based server and a path crafted for that shell's parsing rules; non-shell servers and paths fully neutralized by the selected transformation are not affected. RemotePathTransformation.ShellQuote is available for POSIX shells, while SftpClient avoids a remote shell entirely. This issue is fixed in version 2026.0.0.
Title SSH.NET: ScpClient allows server-side RCE via default SCP path handling
Weaknesses CWE-78
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Sep 16, 2026, 6:34 PM
Reserved
Sep 4, 2026, 2:50 PM
Status
Awaiting Analysis
Published
Sep 16, 2026, 5:18 PM
Modified
Sep 30, 2026, 5:51 PM