Heap Overflow Vulnerability in Microsoft Office
CVE-2026-63533

7.8HIGH

Key Information:

Vendor

Microsoft
Status
Microsoft 365 Apps For Enterprise
Microsoft Office 2016
Microsoft Office 2019
Microsoft Office 365 For Mac
Vendor
CVE Published:
11 August 2026

What is CVE-2026-63533?

A heap-based buffer overflow vulnerability in Microsoft Office permits an unauthorized attacker to execute arbitrary code locally. This vulnerability can potentially lead to unauthorized access to sensitive data or system manipulation, emphasizing the importance of applying security patches issued by the vendor to mitigate risks.

Affected Version(s)

Microsoft 365 Apps for Enterprise 32-bit Systems 16.0.1

Microsoft Office 2016 32-bit Systems 16.0.0 < 16.0.5565.1001

Microsoft Office 2019 32-bit Systems 19.0.0

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

.