CVE-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/<vpnid>/<common_name> 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.

CVSS v3 5.9 MEDIUM

5.9^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 1.6 / Impact : 4.2

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact HIGH

Availability Impact LOW

Scope UNCHANGED

References

Link	Resource
https://github.com/opnsense/core/commit/3af496143a19153c18b2f9458b2510d58aff2b98
https://github.com/opnsense/core/commit/6101b3e2c90482111f420a47775c14a447441a72
https://github.com/opnsense/core/security/advisories/GHSA-2m9v-p7r9-gfcw
https://github.com/opnsense/core/security/advisories/GHSA-2m9v-p7r9-gfcw

Configurations

No configuration.

History

15 Oct 2026, 17:17

Type	Values Removed	Values Added
References	~~() https://github.com/opnsense/core/security/advisories/GHSA-2m9v-p7r9-gfcw -~~	() https://github.com/opnsense/core/security/advisories/GHSA-2m9v-p7r9-gfcw -

15 Oct 2026, 16:18

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-10-15 16:18

Updated : 2026-10-15 21:08

NVD link : CVE-2026-58393

Mitre link : CVE-2026-58393

CVE.ORG link : CVE-2026-58393

JSON object : View

Products Affected

No product.

CWE

CWE-22

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

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