Use After Free Vulnerability in Microsoft Office Excel
CVE-2026-20950

7.8HIGH

Key Information:

Vendor

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

What is CVE-2026-20950?

A vulnerability exists in Microsoft Office Excel that allows unauthorized attackers to leverage a use after free condition. This flaw can lead to the execution of arbitrary code, potentially allowing attackers to take control of the affected system. Users are advised to apply the latest security patches to mitigate risks and enhance system security.

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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