Path Traversal Vulnerability in OpenVPN Client Specific Override on OPNsense Firewall

CVE-2026-58393

What is CVE-2026-58393?

A path traversal vulnerability exists in the OpenVPN Client Specific Override functionality of OPNsense Firewall. The issue arises from the common_name field accepting path traversal sequences and the openvpn_csc_conf_write() function improperly concatenating the values into specified directories without normalization checks. This flaw allows authenticated users with Client Specific Override privileges to manipulate the configuration file path, potentially leading to the creation of configuration files outside of the intended directory. To exploit this vulnerability successfully, the attacker must cause a corresponding OpenVPN client-connect or authentication event. The issue has been addressed in OPNsense version 26.1.11.

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