Use After Free Vulnerability in Microsoft Office by Microsoft
CVE-2026-20953

8.4HIGH

Key Information:

Vendor

Microsoft
Status
Microsoft Office 2019
Microsoft 365 Apps For Enterprise
Microsoft Office Ltsc 2024
Microsoft Office Ltsc 2021
Vendor
CVE Published:
13 January 2026

What is CVE-2026-20953?

A use after free vulnerability exists in Microsoft Office, where an attacker can exploit this flaw to execute arbitrary code locally. This allows unauthorized access to the affected system, compromising its integrity and security. Promptly applying patches from Microsoft is crucial to mitigate the risks associated with this vulnerability.

Affected Version(s)

Microsoft 365 Apps for Enterprise x64-based Systems 16.0.1

Microsoft Office 2016 32-bit Systems 16.0.0 < 16.0.5535.1000

Microsoft Office 2019 x64-based Systems 19.0.0

References

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

CVSS V3.1

Score:
8.4
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Local
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

JSON
.