Integer Underflow Vulnerability in Microsoft Office Excel
CVE-2026-45469

7.8HIGH

Key Information:

Vendor

Microsoft
Status
Microsoft 365 Apps For Enterprise
Microsoft Excel 2016
Microsoft Office 2019
Microsoft Office 365 For Mac
Vendor
CVE Published:
9 June 2026

What is CVE-2026-45469?

An integer underflow vulnerability in Microsoft Office Excel could allow an unauthorized attacker to execute local code. This flaw can be exploited through specially crafted data, posing significant risks to systems that handle sensitive information. Users are urged to apply patches promptly to mitigate potential threats.

Affected Version(s)

Microsoft 365 Apps for Enterprise 32-bit Systems 16.0.1

Microsoft Excel 2016 32-bit Systems 16.0.0.0 < 16.0.5556.1001

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

.