Heap-Based Buffer Overflow in Microsoft Excel Software by Microsoft
CVE-2026-81397

7.8HIGH

Key Information:

Vendor

Microsoft
Status
Microsoft 365 Apps For Enterprise
Microsoft Excel 2016
Microsoft Office 2016
Microsoft Office 2019
Vendor
CVE Published:
8 September 2026

What is CVE-2026-81397?

A heap-based buffer overflow vulnerability exists in Microsoft Office Excel that allows an unauthorized attacker to manipulate memory allocations. This flaw can lead to the execution of arbitrary code on the local machine when users open specially crafted Excel files. It is crucial for users to update their software to mitigate potential risks associated with this vulnerability.

Affected Version(s)

Microsoft 365 Apps for Enterprise 32-bit Systems 16.0.1 < 16.0.20326.20138

Microsoft Excel 2016 32-bit Systems 16.0.0.0 < 16.0.5569.1003

Microsoft Office 2016 32-bit Systems 16.0.0 < 16.0.5569.1003

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

.