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TI-2026-58836 Aliases CVE-2026-85756GHSA-mggc-4xg6-vcxf

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

Priority LOW 36CWE-78Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
High
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-78.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00617 49th percentileScored 2026-11-07
Fix Fixed SSH.NET (sshnet): 2026.0.0SSH.NET (NuGet): 2026.0.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
sshnetSSH.NETbefore 2026.0.02026.0.0Patch availableCNA
—SSH.NET (NuGet)before 2026.0.02026.0.0Patch availableGHSA-mggc-4xg6-vcxf
  • SSH.NET Vendorsshnet Affected before 2026.0.0 Fixed in 2026.0.0 Patch available CNA
  • SSH.NET (NuGet) Vendor— Affected before 2026.0.0 Fixed in 2026.0.0 Patch available GHSA-mggc-4xg6-vcxf

Remediation

  • Fix · CNA SSH.NET (sshnet) Fixed in 2026.0.0
  • Fix · GHSA-mggc-4xg6-vcxf SSH.NET (NuGet) Fixed in 2026.0.0 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-85756
  2. 2026-10-03 Alias added: GHSA-mggc-4xg6-vcxf

References

Advisory 1

Other 4

  • TI-2026-36068 SSH.NET: ScpClient Recursive Download Allows Arbitrary File Write via Server-Controlled SCP Filenames CVSS 3.1HIGH 7.1

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences