CVE-2026-40366: Microsoft 365 Apps

High severity, CVSS 8.4. EPSS: 0.4% chance of exploitation in the next 30 days.

Access of resource using incompatible type ('type confusion') in Microsoft Office Word allows an unauthorized attacker to execute code locally.

Affected products

• Microsoft 365 Apps: affected versions not specified
• Microsoft Office: version 2019 only
• Microsoft Office Long Term Servicing Channel: version 2021 only; version 2024 only
• Microsoft Word: version 2016 only

Published 2026-05-12. Last modified 2026-06-17.