CVE-2026-81959 – Microsoft Excel Remote Code Execution Vulnerability

CVSS 7.8 IMPORTANT Critical - Same Day Deployment

“A malicious Excel file could turn one successful click into code execution with high impact to data and systems.”

CVE-2026-81959 is a Critical remote code execution vulnerability affecting Microsoft Excel and multiple Microsoft Office releases. A heap-based buffer overflow involving integer overflow or wraparound can allow an unauthorized attacker to execute code locally. Exploitation requires a user to open a malicious Office file, but the attacker does not require prior privileges. The Preview Pane is not an attack vector.

Key Details

Affected Product
Microsoft 365 Apps
Attack Vector
Local
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
CWE Classification
CWE-122
Patch this CVE on all your endpoints in under 5 minutes. First 200 endpoints are free forever, scale as needed.