Use After Free Vulnerability in Microsoft Office Word by Microsoft
CVE-2026-55128

7.8HIGH

Key Information:

Vendor

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

What is CVE-2026-55128?

A use after free vulnerability in Microsoft Office Word allows an unauthorized attacker to execute arbitrary code on a targeted system. This occurs when the application attempts to use memory that has already been freed, creating a potential attack vector for malicious actors. It is crucial for users to apply security updates promptly to mitigate risks associated with this vulnerability.

Affected Version(s)

Microsoft 365 Apps for Enterprise 32-bit Systems 16.0.1

Microsoft Office 2019 32-bit Systems 19.0.0

Microsoft Office 365 for Mac 1.0.0 < 16.111.26071215

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

.