CVE-2026-50678: Microsoft 365 Apps

Low severity, CVSS 3.3. EPSS: 0.5% chance of exploitation in the next 30 days.

Heap-based buffer overflow in Microsoft Office Excel allows an unauthorized attacker to disclose information locally.

Affected products

• Microsoft 365 Apps: affected versions not specified
• Microsoft Excel: version 2016 only
• Microsoft Microsoft 365: affected versions not specified
• Microsoft Office 2019: affected versions not specified
• Microsoft Office 2021: affected versions not specified
• Microsoft Office 2024: affected versions not specified
• Microsoft Office Online Server: before 16.0.10417.20175 (fixed in 16.0.10417.20175)

Published 2026-07-14. Last modified 2026-07-15.