Information Disclosure Vulnerability in Microsoft Office Excel
CVE-2026-21261

5.5MEDIUM

Key Information:

Vendor

Microsoft
Status
Microsoft 365 Apps For Enterprise
Microsoft Excel 2016
Microsoft Office 2019
Microsoft Office Ltsc 2021
Vendor
CVE Published:
10 February 2026

What is CVE-2026-21261?

An out-of-bounds read vulnerability in Microsoft Office Excel could allow an unauthorized attacker to disclose sensitive information locally. Exploitation of this vulnerability may enable attackers to gain access to restricted data, posing a significant risk to user privacy and data integrity. It is crucial for users and organizations using affected versions of Excel to apply the latest security updates provided by Microsoft to mitigate these risks.

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Deploy the Patch

Affected Version(s)

Microsoft 365 Apps for Enterprise 32-bit Systems 16.0.1

Microsoft Excel 2016 32-bit Systems 16.0.0.0 < 16.0.5539.1002

Microsoft Office 2019 32-bit Systems 19.0.0

References

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

CVSS V3.1

Score:
5.5
Severity:
MEDIUM
Confidentiality:
High
Integrity:
None
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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