Rubygem-mqtt: rubygem-mqtt hostname validation

{
  "id": "1c4b047da865b59c5e60941f5e18a615fe50eb7f4b5ee4a735daeba2195db23e",
  "url": "https://osv.dev/vulnerability/CVE-2025-12790",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Rubygem-mqtt: rubygem-mqtt hostname validation",
    "summary": "A flaw was found in Rubygem MQTT. By default, the package used to not have hostname validation, resulting in possible Man-in-the-Middle (MITM) attack.",
    "evidence": "osv:CVE-2025-12790",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2025-12790",
      "aliases": [
        "CVE-2025-12790",
        "GHSA-9c5q-w6gr-fxcq"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/njh/ruby-mqtt",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "f99f2c9dcd4f388d4313c9fccbb6eb288701dee7"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "0.7.0"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v0.6.0",
            "v0.5.0",
            "v0.4.0",
            "v0.3.1",
            "v0.3.0",
            "v0.2.0",
            "v0.1.0",
            "v0.0.9",
            "v0.0.8",
            "v0.0.7",
            "v0.0.6",
            "v0.0.5"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-12790.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:51.604298966Z",
      "provider": "osv",
      "references": [
        "https://access.redhat.com/downloads/content/package-browser/",
        "https://github.com/njh/ruby-mqtt/blob/main/NEWS.md#ruby-mqtt-version-070-2025-10-29",
        "https://access.redhat.com/security/cve/CVE-2025-12790",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/12xxx/CVE-2025-12790.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2025-12790",
        "https://bugzilla.redhat.com/show_bug.cgi?id=2413004",
        "https://github.com/njh/ruby-mqtt"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-29"
        ],
        "cna_assigner": "redhat",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/12xxx/CVE-2025-12790.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2025-12790",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 520434,
  "published_at": "2025-11-06T21:07:34.97+00:00"
}