Integer Overflow Vulnerability in Microsoft Office
CVE-2026-64911

7.8HIGH

Key Information:

Vendor

Microsoft
Status
Microsoft 365 Apps For Enterprise
Microsoft Office 2019
Microsoft Office 365 For Mac
Microsoft Office Ltsc 2021
Vendor
CVE Published:
11 August 2026

What is CVE-2026-64911?

An integer overflow vulnerability in Microsoft Office permits unauthorized attackers to execute arbitrary code on affected systems. By exploiting this flaw, a malicious actor can manipulate how the application processes integers, potentially leading to unexpected behavior or local code execution. Users are advised to apply updates to mitigate the risk associated with this vulnerability.

Affected Version(s)

Microsoft 365 Apps for Enterprise 32-bit Systems 16.0.1

Microsoft Office 2019 32-bit Systems 19.0.0

Microsoft Office 365 for Mac 1.0.0 < 16.112.26081010

References

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

CVSS V3.1

Score:
7.8
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Local
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
Required
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.