CVE-2026-48798 PUBLISHED

SSH.NET is a Secure Shell (SSH) library for .NET. In 2025.1.0 and earlier, ScpClient.Download(string directoryName, DirectoryInfo directoryInfo) trusts file and directory names returned by a remote SCP server and combines them with the requested local directory without containment validation, allowing a malicious, compromised, or man-in-the-middle server to use ../ sequences or absolute paths to create or overwrite files anywhere writable by the client process. This issue is fixed in version 2026.0.0.

• https://github.com/sshnet/SSH.NET/security/advisories/GHSA-q939-rpr3-3284
• https://github.com/sshnet/SSH.NET/commit/600be0de543765995a189b5d7cd4efac5007f3ce
• https://github.com/sshnet/SSH.NET/releases/tag/2026.0.0

• CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') CWE
• CWE-73: External Control of File Name or Path CWE