CVE-2026-66349

{
  "id": "CVE-2026-66349",
  "sourceIdentifier": "[email protected]",
  "published": "2026-07-30T23:16:52.920",
  "lastModified": "2026-10-23T23:10:00.157",
  "vulnStatus": "Deferred",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "The MMS server connection handler contains a flaw in its processing of \nBER-encoded request data. When an MMS confirmed request PDU containing \nan extended BER tag is received over an established session, the decoder\n may advance its internal buffer incorrectly due to a missing bounds \ncheck. This results in a one byte heap out-of-bounds read and causes the\n MMS service process to terminate, leading to a denial-of-service \ncondition."
    },
    {
      "lang": "es",
      "value": "El gestor de conexión del servidor MMS contiene una falla en su procesamiento de datos de solicitud codificados en BER. Cuando se recibe una PDU de solicitud confirmada de MMS que contiene una etiqueta BER extendida a través de una sesión establecida, el decodificador puede avanzar su búfer interno incorrectamente debido a una falta de verificación de límites. Esto resulta en una lectura fuera de límites de un byte en el heap y causa la terminación del proceso del servicio MMS, lo que lleva a una condición de denegación de servicio."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "MZ Automation GmbH",
          "product": "libiec61850",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "0",
              "lessThan": "1.6.2",
              "versionType": "custom",
              "status": "affected"
            },
            {
              "version": "1.6.2",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV40": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "4.0",
          "vectorString": "CVSS:4.0/AV:A/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
          "baseScore": 6.9,
          "baseSeverity": "MEDIUM",
          "attackVector": "ADJACENT",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "vulnConfidentialityImpact": "NONE",
          "vulnIntegrityImpact": "NONE",
          "vulnAvailabilityImpact": "HIGH",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "subAvailabilityImpact": "NONE",
          "exploitMaturity": "NOT_DEFINED",
          "confidentialityRequirement": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "availabilityRequirement": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "valueDensity": "NOT_DEFINED",
          "vulnerabilityResponseEffort": "NOT_DEFINED",
          "providerUrgency": "NOT_DEFINED"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "baseScore": 6.5,
          "baseSeverity": "MEDIUM",
          "attackVector": "ADJACENT_NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 3.6
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-07-31T15:53:07.188073Z",
          "id": "CVE-2026-66349",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-125"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-211-10.json",
      "source": "[email protected]"
    },
    {
      "url": "https://www.cisa.gov/news-events/ics-advisories/icsa-26-211-10",
      "source": "[email protected]"
    }
  ]
}