Findings

CVE-2026-58393

OPNsense is a FreeBSD based firewall and routing platform.

Published Oct 15, 2026 · updated Oct 15, 2026

OPNsense is a FreeBSD based firewall and routing platform. Prior to version 26.1.11, the OpenVPN Client Specific Override common_name field accepts path traversal sequences and openvpn_csc_conf_write() concatenates the value into /var/etc/openvpn-csc/ / without normalization or a basename check. The affected event handlers are client_connect.php and user_pass_verify.php. An authenticated user with Client Specific Override privileges can store the traversal value, and a matching OpenVPN client-connect or authentication event causes a generated CSO file to be written outside the intended directory. The file content is generated OpenVPN configuration rather than arbitrary bytes, and practical exploitation requires the attacker to cause a matching common name or username to be processed. This issue is fixed in version 26.1.11.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Oct 15, 2026 · NIST NVD

    Detected

    OPNsense is a FreeBSD based firewall and routing platform. Prior to version 26.1.11, the OpenVPN Client Specific Override common_name field accepts path traversal sequences and openvpn_csc_conf_write() concatenates the value into /var/etc/openvpn-csc/ / without normalization or a basename check. The affected event handlers are client_connect.php and user_pass_verify.php. An authenticated user with

  2. Oct 15, 2026 · NIST NVD

    Updated

    OPNsense is a FreeBSD based firewall and routing platform. Prior to version 26.1.11, the OpenVPN Client Specific Override common_name field accepts path traversal sequences and openvpn_csc_conf_write() concatenates the value into /var/etc/openvpn-csc/ / without normalization or a basename check. The affected event handlers are client_connect.php and user_pass_verify.php. An authenticated user with

Sources

  • CVE.orgVulnerability recordCVE-2026-58393

    Official CVE identifier

    cve.org
  • NIST NVDVulnerability recordCVE-2026-58393

    OPNsense is a FreeBSD based firewall and routing platform. Prior to version 26.1.11, the OpenVPN Client Specific Override common_name field accepts path traversal sequences and openvpn_csc_conf_write() concatenates the value into /var/etc/openvpn-csc/ / without

    nvd.nist.gov

References

CVE-2026-58393 · ZeroDay Findings