« Volver al listado

CVE-2026-55044

Estado: AnalizadaAlta (7.8)—

Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to execute code locally.

CVSS

Probabilidad de explotación (EPSS)

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

Vector CVSS con AV:L, UI:R indica explotación en cliente (T1203): abrir archivo Excel preparado. El CWE-125 (lectura fuera de límites) en Excel permite ejecución de código (T1059) y acceso a datos en memoria (T1005).

Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.

🛡️ Mitigaciones ATT&CK que cubren estas técnicas

Restrict Web-Based ContentPrivileged Account ManagementLimit Software InstallationExecution PreventionBehavior Prevention on EndpointDisable or Remove Feature or Program

Tecnologías afectadas (7)

Microsoft — 365 AppsMicrosoft — ExcelMicrosoft — Microsoft 365Microsoft — Office 2019Microsoft — Office 2021Microsoft — Office 2024Microsoft — Office Online Server

CWE

Referencias

JSON original (NVD)

Mostrar
{
  "id": "CVE-2026-55044",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-55044",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-07-15T03:56:14.795058Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "secure@microsoft.com",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 7.8,
          "attackVector": "LOCAL",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "REQUIRED",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.9,
        "exploitabilityScore": 1.8
      }
    ]
  },
  "affected": [
    {
      "source": "secure@microsoft.com",
      "affectedData": [
        {
          "vendor": "Microsoft",
          "product": "Microsoft 365 Apps for Enterprise",
          "versions": [
            {
              "status": "affected",
              "version": "16.0.1",
              "lessThan": "https://aka.ms/OfficeSecurityReleases",
              "versionType": "custom"
            }
          ],
          "platforms": [
            "32-bit Systems",
            "x64-based Systems"
          ]
        },
        {
          "vendor": "Microsoft",
          "product": "Microsoft Excel 2016",
          "versions": [
            {
              "status": "affected",
              "version": "16.0.0.0",
              "lessThan": "16.0.5561.1001",
              "versionType": "custom"
            }
          ],
          "platforms": [
            "32-bit Systems",
            "x64-based Systems"
          ]
        },
        {
          "vendor": "Microsoft",
          "product": "Microsoft Office 2019",
          "versions": [
            {
              "status": "affected",
              "version": "19.0.0",
              "lessThan": "https://aka.ms/OfficeSecurityReleases",
              "versionType": "custom"
            }
          ],
          "platforms": [
            "32-bit Systems",
            "x64-based Systems"
          ]
        },
        {
          "vendor": "Microsoft",
          "product": "Microsoft Office 365 for Mac",
          "versions": [
            {
              "status": "affected",
              "version": "1.0.0",
              "lessThan": "16.111.26071215",
              "versionType": "custom"
            }
          ]
        },
        {
          "vendor": "Microsoft",
          "product": "Microsoft Office LTSC 2021",
          "versions": [
            {
              "status": "affected",
              "version": "16.0.1",
              "lessThan": "https://aka.ms/OfficeSecurityReleases",
              "versionType": "custom"
            }
          ],
          "platforms": [
            "32-bit Systems",
            "x64-based Systems"
          ]
        },
        {
          "vendor": "Microsoft",
          "product": "Microsoft Office LTSC 2024",
          "versions": [
            {
              "status": "affected",
              "version": "16.0.0",
              "lessThan": "https://aka.ms/OfficeSecurityReleases",
              "versionType": "custom"
            }
          ],
          "platforms": [
            "32-bit Systems",
            "x64-based Systems"
          ]
        },
        {
          "vendor": "Microsoft",
          "product": "Microsoft Office LTSC for Mac 2021",
          "versions": [
            {
              "status": "affected",
              "version": "16.0.1",
              "lessThan": "16.111.26071215",
              "versionType": "custom"
            }
          ]
        },
        {
          "vendor": "Microsoft",
          "product": "Microsoft Office LTSC for Mac 2024",
          "versions": [
            {
              "status": "affected",
              "version": "16.0.0",
              "lessThan": "16.111.26071215",
              "versionType": "custom"
            }
          ]
        },
        {
          "vendor": "Microsoft",
          "product": "Office Online Server",
          "versions": [
            {
              "status": "affected",
              "version": "16.0.0.0",
              "lessThan": "16.0.10417.20175",
              "versionType": "custom"
            }
          ]
        }
      ]
    }
  ],
  "published": "2026-07-14T18:18:16.043",
  "references": [
    {
      "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55044",
      "tags": [
        "Vendor Advisory",
        "Patch"
      ],
      "source": "secure@microsoft.com"
    }
  ],
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "secure@microsoft.com",
      "description": [
        {
          "lang": "en",
          "value": "CWE-125"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to execute code locally."
    }
  ],
  "lastModified": "2026-07-16T11:54:34.857",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:microsoft:365_apps:-:*:*:*:enterprise:*:x64:*",
              "vulnerable": true,
              "matchCriteriaId": "3259EBFE-AE2D-48B8-BE9A-E22BBDB31378"
            },
            {
              "criteria": "cpe:2.3:a:microsoft:365_apps:-:*:*:*:enterprise:*:x86:*",
              "vulnerable": true,
              "matchCriteriaId": "CD25F492-9272-4836-832C-8439EBE64CCF"
            },
            {
              "criteria": "cpe:2.3:a:microsoft:excel:2016:*:*:*:*:*:x64:*",
              "vulnerable": true,
              "matchCriteriaId": "CD88F667-6773-4DB7-B6C3-9C7B769C0808"
            },
            {
              "criteria": "cpe:2.3:a:microsoft:excel:2016:*:*:*:*:*:x86:*",
              "vulnerable": true,
              "matchCriteriaId": "B342EF98-B414-44D0-BAFB-FCA24294EECE"
            },
            {
              "criteria": "cpe:2.3:a:microsoft:microsoft_365:-:*:*:*:*:macos:*:*",
              "vulnerable": true,
              "matchCriteriaId": "12418BDE-FA2E-4BBF-8E47-45C505399898"
            },
            {
              "criteria": "cpe:2.3:a:microsoft:office_2019:-:*:*:*:*:*:x64:*",
              "vulnerable": true,
              "matchCriteriaId": "241CDE2B-ABD0-4EFF-8D73-1766E32FA20F"
            },
            {
              "criteria": "cpe:2.3:a:microsoft:office_2019:-:*:*:*:*:*:x86:*",
              "vulnerable": true,
              "matchCriteriaId": "14D63E3F-A431-4DD8-979F-811E8DAC423D"
            },
            {
              "criteria": "cpe:2.3:a:microsoft:office_2021:-:*:*:*:ltsc:-:x64:*",
              "vulnerable": true,
              "matchCriteriaId": "1D518075-3362-4D15-93B1-0E6C61518D16"
            },
            {
              "criteria": "cpe:2.3:a:microsoft:office_2021:-:*:*:*:ltsc:-:x86:*",
              "vulnerable": true,
              "matchCriteriaId": "1059BEC6-C30B-4F0F-A878-5267A21CBD85"
            },
            {
              "criteria": "cpe:2.3:a:microsoft:office_2021:-:*:*:*:ltsc:macos:-:*",
              "vulnerable": true,
              "matchCriteriaId": "0DB3EBBF-E0C4-4D5A-8D22-107463AD1DE4"
            },
            {
              "criteria": "cpe:2.3:a:microsoft:office_2024:-:*:*:*:ltsc:-:x64:*",
              "vulnerable": true,
              "matchCriteriaId": "55A9AFDA-D77B-4CC7-ACE5-3A2ABDA257D8"
            },
            {
              "criteria": "cpe:2.3:a:microsoft:office_2024:-:*:*:*:ltsc:-:x86:*",
              "vulnerable": true,
              "matchCriteriaId": "8887D177-26A3-4008-89B6-50A9E9830F13"
            },
            {
              "criteria": "cpe:2.3:a:microsoft:office_2024:-:*:*:*:ltsc:macos:-:*",
              "vulnerable": true,
              "matchCriteriaId": "589B470B-9C2E-41E2-A44D-D8CCB4D2F933"
            },
            {
              "criteria": "cpe:2.3:a:microsoft:office_online_server:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "746CEA14-C3AC-4256-A71D-BCA3A43459F8",
              "versionEndExcluding": "16.0.10417.20175"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "secure@microsoft.com"
}