Heap-based Buffer Overflow Vulnerability in Microsoft Office Word
CVE-2026-108439

8.8HIGH

Key Information:

Vendor

Microsoft
Status
Microsoft 365 Apps For Enterprise
Microsoft Office 365 For Mac
Microsoft Office Ltsc 2021
Microsoft Office Ltsc 2024
Vendor
CVE Published:
15 October 2026

What is CVE-2026-108439?

A heap-based buffer overflow vulnerability in Microsoft Office Word allows remote attackers to exploit the application and execute unauthorized code. This can occur when the application processes specially crafted documents sent over a network, granting attackers unintended control over affected systems. Proper patching and security measures are essential to mitigate the risk associated with this vulnerability.

Affected Version(s)

Microsoft 365 Apps for Enterprise 32-bit Systems 16.0.1

Microsoft Office 365 for Mac 1.0.0 < 16.114.26101123

Microsoft Office LTSC 2021 32-bit Systems 16.0.1 < 16.0.14334.20974

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE...
vendor-advisorypatch

CVSS V3.1

Score:
8.8
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
Required
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.