Vulnerability-Lookup

FKIE_CVE-2026-58393

Vulnerability from fkie_nvd - Published: 2026-10-15 16:18 - Updated: 2026-10-15 21:08

Severity

5.9 (Medium) - CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:L

Summary

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.

References

	URL	Tags
	security-advisories@github.com	https://github.com/opnsense/core/commit/3af496143a19153c18b2f9458b2510d58aff2b98
	security-advisories@github.com	https://github.com/opnsense/core/commit/6101b3e2c90482111f420a47775c14a447441a72
	security-advisories@github.com	https://github.com/opnsense/core/security/advisories/GHSA-2m9v-p7r9-gfcw
	134c704f-9b21-4f2e-91b3-4a467353bcc0	https://github.com/opnsense/core/security/advisories/GHSA-2m9v-p7r9-gfcw

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "core",
          "vendor": "opnsense",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 26.1.11"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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/\u003cvpnid\u003e/\u003ccommon_name\u003e 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."
    }
  ],
  "id": "CVE-2026-58393",
  "lastModified": "2026-10-15T21:08:49.703",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "NETWORK",
          "availabilityImpact": "LOW",
          "baseScore": 5.9,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:L",
          "version": "3.1"
        },
        "exploitabilityScore": 1.6,
        "impactScore": 4.2,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-58393",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-10-15T16:07:43.427308Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-10-15T16:18:18.310",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/opnsense/core/commit/3af496143a19153c18b2f9458b2510d58aff2b98"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/opnsense/core/commit/6101b3e2c90482111f420a47775c14a447441a72"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/opnsense/core/security/advisories/GHSA-2m9v-p7r9-gfcw"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "url": "https://github.com/opnsense/core/security/advisories/GHSA-2m9v-p7r9-gfcw"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-22"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}

CVE-2026-58393 (GCVE-0-2026-58393)

Vulnerability from cvelistv5 – Published: 2026-10-15 15:15 – Updated: 2026-10-15 16:07

Title

OPNsense: OpenVPN Client Specific Override common_name allows path traversal in generated CSO files

Summary

Severity

5.9 (Medium)


                        
                          CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:L

SSVC

Exploitation: poc Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-10-15 16:07 UTC

CWE

CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Assigner

GitHub_M CNA under the mitre root

CNA scorecard C 72/100 over 7614 records in the last 180 days details

References

3 references

URL	Tags
https://github.com/opnsense/core/security/advisor…	x_refsource_CONFIRM
https://github.com/opnsense/core/commit/3af496143…	x_refsource_MISC
https://github.com/opnsense/core/commit/6101b3e2c…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
opnsense	core	Affected: < 26.1.11

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-58393",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-10-15T16:07:43.427308Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-10-15T16:07:55.688Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://github.com/opnsense/core/security/advisories/GHSA-2m9v-p7r9-gfcw"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "core",
          "vendor": "opnsense",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 26.1.11"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "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/\u003cvpnid\u003e/\u003ccommon_name\u003e 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."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "LOW",
            "baseScore": 5.9,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:L",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-22",
              "description": "CWE-22: Improper Limitation of a Pathname to a Restricted Directory (\u0027Path Traversal\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-15T15:15:45.924Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/opnsense/core/security/advisories/GHSA-2m9v-p7r9-gfcw",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/opnsense/core/security/advisories/GHSA-2m9v-p7r9-gfcw"
        },
        {
          "name": "https://github.com/opnsense/core/commit/3af496143a19153c18b2f9458b2510d58aff2b98",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/opnsense/core/commit/3af496143a19153c18b2f9458b2510d58aff2b98"
        },
        {
          "name": "https://github.com/opnsense/core/commit/6101b3e2c90482111f420a47775c14a447441a72",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/opnsense/core/commit/6101b3e2c90482111f420a47775c14a447441a72"
        }
      ],
      "source": {
        "advisory": "GHSA-2m9v-p7r9-gfcw",
        "discovery": "UNKNOWN"
      },
      "title": "OPNsense: OpenVPN Client Specific Override common_name allows path traversal in generated CSO files"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-58393",
    "datePublished": "2026-10-15T15:15:45.924Z",
    "dateReserved": "2026-06-30T18:19:58.377Z",
    "dateUpdated": "2026-10-15T16:07:55.688Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

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