Out-of-Bounds Read Vulnerability in Microsoft Excel Software by Microsoft
CVE-2026-20946

7.8HIGH

Key Information:

Vendor

Microsoft
Status
Microsoft Office 2019
Microsoft 365 Apps For Enterprise
Microsoft Office Ltsc For Mac 2021
Microsoft Office Ltsc 2021
Vendor
CVE Published:
13 January 2026

What is CVE-2026-20946?

An out-of-bounds read vulnerability has been identified in Microsoft Office Excel, which could allow an unauthorized attacker to execute arbitrary code on the affected system. This flaw could occur due to improper validation of input data, potentially leading to unauthorized access to sensitive information or the execution of malicious code. It is critical for users to apply the latest security patches and follow best practices to mitigate any risks associated with this vulnerability.

Affected Version(s)

Microsoft 365 Apps for Enterprise 32-bit Systems 16.0.1

Microsoft Excel 2016 32-bit Systems 16.0.0.0 < 16.0.5535.1000

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

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