CVE-2026-58391 (GCVE-0-2026-58391)

Vulnerability from cvelistv5 – Published: 2026-10-15 15:12 – Updated: 2026-10-15 15:12
VLAI
Title
OPNsense: Stored XSS in Firewall Rules/NAT pages via a HTML-attribute breakout
Summary
OPNsense is a FreeBSD based firewall and routing platform. Prior to version 26.1.11, Firewall Rules and NAT views place stored category names and alias descriptions into HTML title attributes in filter_rule.volt and nat_rule.volt without quote-safe encoding. The response layer uses ENT_NOQUOTES, so a double quote survives and closes the attribute, allowing an event-handler attribute to be added to the existing span. A user with Firewall Categories or Firewall Alias Edit privileges can store a category name or alias description; the category must be assigned to a filter or NAT rule, or the alias must be referenced by a rule source or destination, and the rule must be saved so the affected tooltip is rendered. Script then executes in the session of an administrator or other user who opens the affected Rules or NAT page. The script can access CSRF material and perform authenticated actions as the victim. This issue is fixed in version 26.1.11.
Severity
5.4 (Medium)
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
CWE
  • CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
  • CWE-83 - Improper Neutralization of Script in Attributes in a Web Page
Assigner
GitHub_M CNA under the mitre root
CNA scorecard C 72/100 over 7690 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
opnsense core Affected: < 26.1.11
guessed Create a notification for this product.
Show details on NVD website
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{
  "containers": {
    "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, Firewall Rules and NAT views place stored category names and alias descriptions into HTML title attributes in filter_rule.volt and nat_rule.volt without quote-safe encoding. The response layer uses ENT_NOQUOTES, so a double quote survives and closes the attribute, allowing an event-handler attribute to be added to the existing span. A user with Firewall Categories or Firewall Alias Edit privileges can store a category name or alias description; the category must be assigned to a filter or NAT rule, or the alias must be referenced by a rule source or destination, and the rule must be saved so the affected tooltip is rendered. Script then executes in the session of an administrator or other user who opens the affected Rules or NAT page. The script can access CSRF material and perform authenticated actions as the victim. This issue is fixed in version 26.1.11."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 5.4,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "LOW",
            "integrityImpact": "LOW",
            "privilegesRequired": "LOW",
            "scope": "CHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-79",
              "description": "CWE-79: Improper Neutralization of Input During Web Page Generation (\u0027Cross-site Scripting\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-83",
              "description": "CWE-83: Improper Neutralization of Script in Attributes in a Web Page",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-15T15:12:08.334Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/opnsense/core/security/advisories/GHSA-2xrm-p255-p43h",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/opnsense/core/security/advisories/GHSA-2xrm-p255-p43h"
        },
        {
          "name": "https://github.com/opnsense/core/commit/5e6313f50546474031805039e209830b63b2b0e4",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/opnsense/core/commit/5e6313f50546474031805039e209830b63b2b0e4"
        },
        {
          "name": "https://github.com/opnsense/core/commit/fb3b8a07f407ce281b1dde748706acbb0bc514ce",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/opnsense/core/commit/fb3b8a07f407ce281b1dde748706acbb0bc514ce"
        },
        {
          "name": "https://hackerask.com/posts/opnsense",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://hackerask.com/posts/opnsense"
        }
      ],
      "source": {
        "advisory": "GHSA-2xrm-p255-p43h",
        "discovery": "UNKNOWN"
      },
      "title": "OPNsense: Stored XSS in Firewall Rules/NAT pages via a HTML-attribute breakout"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-58391",
    "datePublished": "2026-10-15T15:12:08.334Z",
    "dateReserved": "2026-06-30T18:19:58.377Z",
    "dateUpdated": "2026-10-15T15:12:08.334Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "nvd": {
      "cve": {
        "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, Firewall Rules and NAT views place stored category names and alias descriptions into HTML title attributes in filter_rule.volt and nat_rule.volt without quote-safe encoding. The response layer uses ENT_NOQUOTES, so a double quote survives and closes the attribute, allowing an event-handler attribute to be added to the existing span. A user with Firewall Categories or Firewall Alias Edit privileges can store a category name or alias description; the category must be assigned to a filter or NAT rule, or the alias must be referenced by a rule source or destination, and the rule must be saved so the affected tooltip is rendered. Script then executes in the session of an administrator or other user who opens the affected Rules or NAT page. The script can access CSRF material and perform authenticated actions as the victim. This issue is fixed in version 26.1.11."
          }
        ],
        "id": "CVE-2026-58391",
        "lastModified": "2026-10-15T16:18:18.030",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "NETWORK",
                "availabilityImpact": "NONE",
                "baseScore": 5.4,
                "baseSeverity": "MEDIUM",
                "confidentialityImpact": "LOW",
                "integrityImpact": "LOW",
                "privilegesRequired": "LOW",
                "scope": "CHANGED",
                "userInteraction": "REQUIRED",
                "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N",
                "version": "3.1"
              },
              "exploitabilityScore": 2.3,
              "impactScore": 2.7,
              "source": "security-advisories@github.com",
              "type": "Secondary"
            }
          ]
        },
        "published": "2026-10-15T16:18:18.030",
        "references": [
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/opnsense/core/commit/5e6313f50546474031805039e209830b63b2b0e4"
          },
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/opnsense/core/commit/fb3b8a07f407ce281b1dde748706acbb0bc514ce"
          },
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/opnsense/core/security/advisories/GHSA-2xrm-p255-p43h"
          },
          {
            "source": "security-advisories@github.com",
            "url": "https://hackerask.com/posts/opnsense"
          }
        ],
        "sourceIdentifier": "security-advisories@github.com",
        "vulnStatus": "Received",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-79"
              },
              {
                "lang": "en",
                "value": "CWE-83"
              }
            ],
            "source": "security-advisories@github.com",
            "type": "Primary"
          }
        ]
      }
    }
  }
}



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