CVE-2026-58393
OPNsense: OpenVPN Client Specific Override common_name allows path traversal in generated CSO files
Description
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.
INFO
Published Date :
Oct. 15, 2026, 4:18 p.m.
Last Modified :
Oct. 15, 2026, 5:17 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | MITRE-CVE | ||||
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update OPNsense to version 26.1.11.
- Ensure OpenVPN client configurations are validated.
- Review access controls for OpenVPN settings.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-58393.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-58393 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-58393
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-58393 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-58393 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Oct. 15, 2026
Action Type Old Value New Value Added Reference https://github.com/opnsense/core/security/advisories/GHSA-2m9v-p7r9-gfcw Added SSVC {'id': 'CVE-2026-58393', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-10-15T16:07:43.427308Z'} -
New CVE Received by [email protected]
Oct. 15, 2026
Action Type Old Value New Value Added Description 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. Added CVSS V3.1 AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:L Added CWE CWE-22 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/58xxx/CVE-2026-58393.json">CVE-2026-58393</a> Added Reference https://github.com/opnsense/core/commit/3af496143a19153c18b2f9458b2510d58aff2b98 Added Reference https://github.com/opnsense/core/commit/6101b3e2c90482111f420a47775c14a447441a72 Added Reference https://github.com/opnsense/core/security/advisories/GHSA-2m9v-p7r9-gfcw