Stack-based Buffer Overflow in Microsoft Office
CVE-2026-66807

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-2026-66807?

A stack-based buffer overflow vulnerability in Microsoft Office facilitates unauthorized code execution. Exploitation of this flaw could allow an attacker to execute arbitrary code on the user's machine, potentially leading to data compromise and unauthorized access to sensitive information. Users are urged to ensure their Microsoft Office applications are updated to mitigate potential risks 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

.