Access Control Bypass in Microsoft Excel Affects Various Versions
CVE-2026-20949

7.8HIGH

Key Information:

Vendor

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

What is CVE-2026-20949?

An improper access control vulnerability in Microsoft Excel allows unauthorized attackers to bypass security features locally. This flaw can lead to unauthorized access to sensitive data, making it imperative for users to apply the latest security patches and updates to mitigate the risk posed by this vulnerability.

Affected Version(s)

Microsoft 365 Apps for Enterprise 32-bit Systems 16.0.1

Microsoft Office LTSC 2021 x64-based Systems 16.0.1

Microsoft Office LTSC 2024 32-bit Systems 16.0.0

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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