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CVE-2026-70291

Status: Awaiting AnalysisCritical (9.8)—

Heap-based buffer overflow in Microsoft Office Outlook allows an unauthorized attacker to execute code over a network.

CVSS

Exploitation probability (EPSS)

FIRST hasn't scored this CVE yet (usual for very recent or rejected CVEs).

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

🎯 ATT&CK techniques

How this vulnerability is exploited and what the attacker gains, in MITRE ATT&CK terms.

El vector AV:N/PR:N/UI:N indica explotación por red sin privilegios ni interacción del usuario; el texto describe ejecución de código sin intérprete concreto, por lo que se usa T1059 genérico.

Inferred by our analysis agent from the official description, CVSS vector and CWE, and checked by a supervisor. May contain errors.

🛡️ ATT&CK mitigations that cover these techniques

Privileged Account ManagementVulnerability ScanningRestrict Web-Based ContentNetwork SegmentationLimit Software InstallationLimit Access to Resource Over Network

Affected technologies (1)

⚠ AI-inferred from the description — NVD hasn't analyzed this CVE yet, these aren't verified CPEs.

Microsoft — OutlookAI

CWEs

References

Raw JSON (NVD)

Show
{
  "id": "CVE-2026-70291",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-70291",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-10-08T00:00:00+00:00"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "secure@microsoft.com",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 9.8,
          "attackVector": "NETWORK",
          "baseSeverity": "CRITICAL",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.9,
        "exploitabilityScore": 3.9
      }
    ]
  },
  "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 Office 365 for Mac",
          "versions": [
            {
              "status": "affected",
              "version": "1.0.0",
              "lessThan": "publication",
              "versionType": "custom"
            }
          ]
        },
        {
          "vendor": "Microsoft",
          "product": "Microsoft Office LTSC 2021",
          "versions": [
            {
              "status": "affected",
              "version": "16.0.1",
              "lessThan": "16.0.14334.20974",
              "versionType": "custom"
            }
          ],
          "platforms": [
            "32-bit Systems",
            "x64-based Systems"
          ]
        },
        {
          "vendor": "Microsoft",
          "product": "Microsoft Office LTSC 2024",
          "versions": [
            {
              "status": "affected",
              "version": "16.0.0",
              "lessThan": "16.0.17932.21056",
              "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": "publication",
              "versionType": "custom"
            }
          ]
        },
        {
          "vendor": "Microsoft",
          "product": "Microsoft Office LTSC for Mac 2024",
          "versions": [
            {
              "status": "affected",
              "version": "16.0.0",
              "lessThan": "publication",
              "versionType": "custom"
            }
          ]
        }
      ]
    }
  ],
  "published": "2026-10-13T19:19:48.817",
  "references": [
    {
      "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-70291",
      "source": "secure@microsoft.com"
    }
  ],
  "vulnStatus": "Awaiting Analysis",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "secure@microsoft.com",
      "description": [
        {
          "lang": "en",
          "value": "CWE-122"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "Heap-based buffer overflow in Microsoft Office Outlook allows an unauthorized attacker to execute code over a network."
    }
  ],
  "lastModified": "2026-10-14T04:18:35.673",
  "sourceIdentifier": "secure@microsoft.com"
}