What is CVE-2026-40420?

CVE-2026-40420 is a security advisory published by Microsoft Security Response Center (MSRC) with Elevation of Privilege severity. Microsoft Office Click-To-Run Elevation of Privilege Vulnerability

Which CVE IDs does CVE-2026-40420 cover?

CVE-2026-40420 covers the following CVE IDs: CVE-2026-40420. Each CVE has its own detail page on EchelonGraph Pulse with the synthesized EG score.

What is the CVSS v3 score of CVE-2026-40420?

CVE-2026-40420 has a CVSS v3 base score of 8.8, published by Microsoft Security Response Center (MSRC).

CVE-2026-40420Elevation of PrivilegeCVSS 8.8

Microsoft Office Click-To-Run Elevation of Privilege Vulnerability

Vendor

Microsoft Security Response Center (MSRC)

Published

May 22, 2026

Last Modified

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🔗 CVE IDs covered (1)

CVE-2026-40420 →

📋 Description

<p>Improper access control in Microsoft Office Click-To-Run allows an authorized attacker to elevate privileges locally.</p>