CVE-2026-59996 OpenBSD CVE debrief

Who should care

Users of OpenSSH versions before 10.4 should review and update their installations to prevent potential file placement in unintended directories. This includes administrators and security teams responsible for maintaining OpenSSH installations.

Technical summary

The vulnerability exists in the scp functionality of OpenSSH before version 10.4. When copying files between two remote destinations, there is a possibility that a file could be placed in the parent directory of the intended target directory. This issue arises due to how scp handles file paths during the copy operation. The CVSS score for this vulnerability is 4.2, classified as MEDIUM severity. The vulnerability can be mitigated by updating OpenSSH to version 10.4 or later.

Defensive priority

Medium priority should be given to updating OpenSSH to version 10.4 or later to mitigate this vulnerability. Additionally, monitoring and review of scp usage and configurations should be conducted.

Recommended defensive actions

• Inventory OpenSSH installations to identify versions before 10.4.
• Update OpenSSH to version 10.4 or later.
• Monitor for unusual file placement in directories.
• Review and adjust scp usage and configurations.
• Verify OpenSSH version in use.
• Check for unauthorized file modifications.
• Implement additional monitoring for suspicious activity.

Evidence notes

Evidence is limited; primary records indicate a potential issue with file placement in OpenSSH before version 10.4. Further verification is recommended. The vulnerability exists in the scp functionality of OpenSSH before version 10.4. When copying files between two remote destinations, there is a possibility that a file could be placed in the parent directory of the intended target directory. This issue arises due to how scp handles file paths during the copy operation.

Official resources