Vulnerability · Published Sep 16, 2026 · Assigned by GitHub_M
CVE-2026-85756SSH.NET: ScpClient allows server-side RCE via default SCP path handling
High 7.5
In plain English
A high-severity OS command injection in SSH.NET from sshnet. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 50% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| NuGet | ssh.net | 2026.0.0 | GHSA-mggc-4xg6-vcxf |
Affected products (as reported)
Weakness: CWE-78 · Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
References
- https://github.com/sshnet/SSH.NET/security/advisories/GHSA-mggc-4xg6-vcxf x_refsource_CONFIRM
- https://github.com/sshnet/SSH.NET/commit/c66b9f8fb06c12e71761e58a577b1e796026310f x_refsource_MISC
- https://github.com/sshnet/SSH.NET/releases/tag/2026.0.0 x_refsource_MISC