May 2026: Microsoft Office Click-To-Run Elevation of Privilege Vulnerability
CVE-2026-40420 Published on May 12, 2026
Microsoft Office Click-To-Run Elevation of Privilege Vulnerability
Use after free in Microsoft Office allows an authorized attacker to elevate privileges locally.
Weakness Type
What is an Authorization Vulnerability?
The software does not restrict or incorrectly restricts access to a resource from an unauthorized actor.
CVE-2026-40420 has been classified to as an Authorization vulnerability or weakness.
Products Associated with CVE-2026-40420
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Affected Versions
Microsoft 365 Apps for Enterprise:- Version 16.0.1 and below https://aka.ms/OfficeSecurityReleases is affected.
- Version 19.0.0 and below https://aka.ms/OfficeSecurityReleases is affected.
- Version 16.0.1 and below https://aka.ms/OfficeSecurityReleases is affected.
- Version 16.0.0 and below https://aka.ms/OfficeSecurityReleases is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.