Heap-Based Buffer Overflow in Microsoft Excel by Microsoft
CVE-2026-81951

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-2026-81951?

A heap-based buffer overflow vulnerability in Microsoft Office Excel can allow unauthorized attackers to execute code locally. This flaw arises when Excel improperly handles certain input, which could lead to potential exploitation. It is recommended that users apply the latest security updates to mitigate the impacts related to 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

.