Heap-Based Buffer Overflow in Microsoft Office Excel by Microsoft
CVE-2026-55947

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:
14 July 2026

What is CVE-2026-55947?

A heap-based buffer overflow vulnerability exists in Microsoft Office Excel, which could allow an unauthorized attacker to execute arbitrary code locally when processing specially crafted files. This flaw poses a significant risk to user data and system integrity, making it imperative for users to apply security updates promptly. For detailed information and remediation guidance, please visit the official Microsoft advisory.

Affected Version(s)

Microsoft 365 Apps for Enterprise 32-bit Systems 16.0.1

Microsoft Excel 2016 32-bit Systems 16.0.0.0 < 16.0.5561.1001

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

.