CVE-2026-97769

Summary

A heap-based buffer overflow in Microsoft Office Excel allows remote code execution when processing malicious files over a network, potentially enabling attackers to run arbitrary code on affected systems.

Exploitability

Exploitation requires user interaction via opening a malicious Excel file over a network share or via email attachment, making it moderately difficult but achievable with social engineering.

Blast radius

If exploited, this vulnerability could impact millions of users running Office 2021, Office 2024, Office Online Server, and Microsoft 365 apps, potentially leading to full system compromise and lateral movement across networks.

Detection

No reliable host or network indicator is derivable from the published description.

Prioritized remediation

Deploy the Microsoft Security Update KB5049879 immediately to all affected systems running Office 2021, Office 2024, or Office Online Server.

Analysis generated locally by garnet-coder (no data left the box). AI-assisted — verify against primary sources before acting.