Executive brief
libssh is a library used by applications to securely transfer files and manage remote systems. A vulnerability in its file transfer component (SCP) allows a malicious server to trick a connecting client into overwriting files on the user's computer outside of the intended folder. This could allow an attacker to replace legitimate configuration files or executables with malicious ones, potentially leading to a full system compromise if the user later runs those files.
Technical details
A path traversal vulnerability exists in the libssh SCP protocol implementation within the ssh_scp_pull_request() function. The issue stems from improper sanitation of file paths received from an SCP server during a download operation. A malicious server can respond with unexpected relative paths (e.g., using dot-dot-slash sequences) that bypass the client's intended destination directory. This allows the server to overwrite local files outside of the working directory. This is a libssh implementation of the same flaw previously identified in OpenSSH as CVE-2019-6111. The vulnerability is fixed in libssh versions 0.11.4 and 0.12.0.
Affected products
- libssh libssh < 0.11.4, < 0.12.0
- Red Hat Enterprise Linux 10 libssh-0.12.0-2.el10
Timeline
- 2026-02-04: disclosed: Reported to Red Hat Bugzilla
- 2026-02-10: patched: libssh versions 0.11.4 and 0.12.0 released
- 2026-03-26: advisory: NVD publication date
- 2026-05-19: patched: Red Hat released security updates for RHEL 10