CVE-2026-26110: Microsoft 365 Apps

High severity, CVSS 7.8. EPSS: 0.4% chance of exploitation in the next 30 days.

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

Affected products

• Microsoft 365 Apps: affected versions not specified
• Microsoft 365 Copilot: before 16.0.19822.20000 (fixed in 16.0.19822.20000)
• Microsoft Office: version 2016 only; version 2019 only
• Microsoft Office Long Term Servicing Channel: version 2021 only; version 2024 only

Published 2026-03-10. Last modified 2026-06-17.