CVE-2026-123375

High (8.8)—

Schedule the patchSeverity High 8.8. No public exploit or active exploitation known.

Vendor advisory· Microsoft MSRC

Severity8.8High · CVSS 3.1

Exploitation probability0.61 %higher than 50% of CVEs · score from Nov 11, 2026

Active exploitationNonot in the CISA catalog · checked Nov 12, 03:00 AM

Public exploitNot knownno public code found

News and reports on Orbitaley

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

Timeline

Built from our own data: NVD, CISA KEV and other exploitation catalogues, FIRST EPSS, public exploits, specialised media and Orbitaley coverage.

Nov 10, 2026CVE record published in NVD
Nov 10, 2026Alert: Microsoft fixes 200 vulnerabilities, including an Outlook flaw CISA confirms is being exploited

ATT&CK techniques

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

ExploitationT1203 Exploitation for Client Executionexecution85 %
Primary impactT1059 Command and Scripting Interpreterexecution75 %

El vector UI:R con AV:N y PR:N exige interacción del usuario (T1203); la descripción indica ejecución de código sin nombrar intérprete, 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

Restrict Web-Based Content Privileged Account Management Limit Software Installation Execution Prevention Behavior Prevention on Endpoint Disable or Remove Feature or Program

Affected technologies (1)

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

Microsoft — Office Outlook^AI

NVD record

NVD status: Awaiting Analysis
Published: Nov 10, 2026
Last modified: Nov 10, 2026
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Weakness (CWE): CWE-121, CWE-191

References

Referencemsrc.microsoft.com/update-guide/vulnerability/CVE-2026-123375

Raw JSON (NVD)

Show

{
  "id": "CVE-2026-123375",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-123375",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-11-10T21:05:36.685612Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "secure@microsoft.com",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 8.8,
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:N/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": 2.8
      }
    ]
  },
  "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 Office LTSC 2021",
          "versions": [
            {
              "status": "affected",
              "version": "16.0.1",
              "lessThan": "16.0.14334.21048",
              "versionType": "custom"
            }
          ],
          "platforms": [
            "32-bit Systems",
            "x64-based Systems"
          ]
        },
        {
          "vendor": "Microsoft",
          "product": "Microsoft Office LTSC 2024",
          "versions": [
            {
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              "version": "16.0.0",
              "lessThan": "16.0.17932.21140",
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          "platforms": [
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            "x64-based Systems"
          ]
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  ],
  "published": "2026-11-10T19:20:40.590",
  "references": [
    {
      "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-123375",
      "source": "secure@microsoft.com"
    }
  ],
  "vulnStatus": "Awaiting Analysis",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "secure@microsoft.com",
      "description": [
        {
          "lang": "en",
          "value": "CWE-121"
        },
        {
          "lang": "en",
          "value": "CWE-191"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "Stack-based buffer overflow in Microsoft Office Outlook allows an unauthorized attacker to execute code over a network."
    }
  ],
  "lastModified": "2026-11-10T21:19:04.750",
  "sourceIdentifier": "secure@microsoft.com"
}