HIGH 8.8 Microsoft
CVE-2026-40420
Microsoft Office Click-To-Run Elevation of Privilege Vulnerability
Microsoft Security Update 2026-May: Microsoft Office Click-To-Run Elevation of Privilege Vulnerability
Affected Products
- Microsoft Office 2019 for 32-bit editions
- Microsoft Office 2019 for 64-bit editions
- Microsoft 365 Apps for Enterprise for 32-bit Systems
- Microsoft 365 Apps for Enterprise for 64-bit Systems
- Microsoft Office LTSC 2021 for 64-bit editions
- Microsoft Office LTSC 2021 for 32-bit editions
- Microsoft Office LTSC 2024 for 32-bit editions
- Microsoft Office LTSC 2024 for 64-bit editions
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40420
- https://nvd.nist.gov/vuln/detail/CVE-2026-40420
This high severity vulnerability with a CVSS score of 8.8 was published on 2026-05-12 via Microsoft. Affected: Microsoft Office 2019 for 32-bit editions, Microsoft Office 2019 for 64-bit editions, Microsoft 365 Apps for Enterprise for 32-bit Systems and 5 more.
vulnfeed aggregates 9166 vulnerabilities from NVD, CISA KEV,
Ubuntu, Debian, Red Hat, Kubernetes, Exploit-DB, OSS-Security, GitHub and OpenStack — updated every 4 hours.