CVE-2026-48711: CWE-88: Improper Neutralization of Argument Delimiters in a Command ('Argument Injection') in libfuse sshfs

SSHFS versions 1.4 through 3.7.5 improperly handle bracketed mount sources such as [-oProxyCommand=CMD]:/path. The function find_base_path() removes brackets but leaves a host value starting with a dash, which is passed directly to the ssh command line. When a path-valued sftp_server is also supplied, ssh interprets the host as an option and the server path as its destination, causing the injected ProxyCommand to execute locally before any SSH connection or authentication. This vulnerability allows arbitrary command execution as the user running sshfs. The vulnerability is resolved in version 3.7.6.

An attacker who can supply a crafted mount source to sshfs with the required sftp_server configuration can execute arbitrary commands locally with the privileges of the user running sshfs. This occurs before any SSH connection or authentication, potentially leading to full compromise of the user's environment. The CVSS 3.1 score is 7.0 (High), reflecting local attack vector, high complexity, no privileges required, user interaction required, and high impact on confidentiality, integrity, and availability.

Upgrade sshfs to version 3.7.6 or later where this vulnerability is fixed. No other mitigations are indicated or required by the vendor advisory. Users should avoid using affected versions and ensure that mount sources are not attacker-controlled.