Use After Free Vulnerability in Microsoft Office Click-To-Run
CVE-2026-40418

7.8HIGH

Key Information:

Vendor

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

What is CVE-2026-40418?

A use after free vulnerability in Microsoft Office Click-To-Run allows an authenticated attacker to exploit memory management errors to elevate their privileges on the local system. This flaw, if exploited, can lead to unauthorized access and the potential manipulation of sensitive data, posing a significant risk to users' environments. Users are urged to apply the patches provided by Microsoft to mitigate 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 LTSC 2021 32-bit Systems 16.0.1

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:
Low
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.