Integer Underflow Vulnerability in Microsoft Office Excel
CVE-2026-97739

8.8HIGH

Key Information:

Vendor

Microsoft
Status
Microsoft 365 Apps For Enterprise
Microsoft Office 365 For Mac
Microsoft Office Ltsc 2021
Microsoft Office Ltsc 2024
Vendor
CVE Published:
13 October 2026

What is CVE-2026-97739?

An integer underflow vulnerability exists in Microsoft Office Excel, which can allow an unauthorized attacker to execute arbitrary code remotely. This vulnerability can be exploited when handling specific data inputs, enabling attackers to manipulate memory resources leading to potential unauthorized access and operations within a system. Organizations should apply the recommended patches promptly to mitigate potential threats associated with this flaw.

Affected Version(s)

Microsoft 365 Apps for Enterprise 32-bit Systems 16.0.1

Microsoft Office 365 for Mac 1.0.0 < 16.114.26101123

Microsoft Office LTSC 2021 32-bit Systems 16.0.1 < 16.0.14334.20974

References

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

CVSS V3.1

Score:
8.8
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
Required
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.