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CVE-2026-108438

Status: AnalyzedMedium (6.5)—
Severity6.5Medium · CVSS 3.1
Exploitation probability0.51 %higher than 43% of CVEs
Active exploitationNonot in the CISA catalog
Public exploitNot knownno public code found

Use after free in Microsoft Office Word allows an unauthorized attacker to disclose information over a network.

CVSS

Base score
6.5
Version
3.1
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

Exploitation probability (EPSS)

Probability of exploitation in the next 30 days
0.51 %
Percentile among all scored CVEs
43
Score date
10/20/2026

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 es AV:N/PR:N/UI:R (requiere interacción del usuario) y la descripción solo indica divulgación de información; no menciona ejecución de comandos, así que descarto T1059 de la pista.

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

Application Isolation and SandboxingExploit ProtectionUpdate SoftwareData Loss Prevention

Affected technologies (4)

Microsoft — 365 AppsMicrosoft — Microsoft 365Microsoft — Office 2021Microsoft — Office 2024

CWEs

References

Show 1 references

Raw JSON (NVD)

Show
{
  "id": "CVE-2026-108438",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-108438",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-10-16T01:00:36.768671Z"
        }
      }
    ],
    "cvssMetricV31": [
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          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N",
          "integrityImpact": "NONE",
          "userInteraction": "REQUIRED",
          "attackComplexity": "LOW",
          "availabilityImpact": "NONE",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 3.6,
        "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 365 for Mac",
          "versions": [
            {
              "status": "affected",
              "version": "1.0.0",
              "lessThan": "16.114.26101123",
              "versionType": "custom"
            }
          ]
        },
        {
          "vendor": "Microsoft",
          "product": "Microsoft Office LTSC for Mac 2021",
          "versions": [
            {
              "status": "affected",
              "version": "16.0.1",
              "lessThan": "16.114.26101123",
              "versionType": "custom"
            }
          ]
        },
        {
          "vendor": "Microsoft",
          "product": "Microsoft Office LTSC for Mac 2024",
          "versions": [
            {
              "status": "affected",
              "version": "16.0.0",
              "lessThan": "16.114.26101123",
              "versionType": "custom"
            }
          ]
        }
      ]
    }
  ],
  "published": "2026-10-15T21:17:09.260",
  "references": [
    {
      "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-108438",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "secure@microsoft.com"
    }
  ],
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "secure@microsoft.com",
      "description": [
        {
          "lang": "en",
          "value": "CWE-416"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "Use after free in Microsoft Office Word allows an unauthorized attacker to disclose information over a network."
    }
  ],
  "lastModified": "2026-10-20T12:27:43.800",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
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              "criteria": "cpe:2.3:a:microsoft:365_apps:-:*:*:*:enterprise:*:x64:*",
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              "matchCriteriaId": "CD25F492-9272-4836-832C-8439EBE64CCF"
            },
            {
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              "vulnerable": true,
              "matchCriteriaId": "12418BDE-FA2E-4BBF-8E47-45C505399898"
            },
            {
              "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:macos:-:*",
              "vulnerable": true,
              "matchCriteriaId": "589B470B-9C2E-41E2-A44D-D8CCB4D2F933"
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          ],
          "operator": "OR"
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  "sourceIdentifier": "secure@microsoft.com"
}