CVE-2026-97751

Summary

A heap-based buffer overflow in Microsoft Office Excel allows remote attackers to execute arbitrary code when processing malicious Excel files. This vulnerability is particularly dangerous because it can be triggered over a network without user interaction, making it ideal for remote exploitation.

Exploitability

Exploitation is moderately difficult and requires an attacker to deliver a specially crafted Excel file to a victim, but the attack can be fully automated with no user interaction once the file is opened, making it highly suitable for phishing campaigns or drive-by downloads.

Blast radius

The vulnerability affects all Microsoft 365 apps, Office 2021, Office 2024, and Office Online Server, potentially impacting thousands of users across an organization with minimal security controls, especially in environments where Excel files are frequently shared or opened from untrusted sources.

Detection

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

Prioritized remediation

Deploy the Microsoft Security Update KB5043798 for Office 2021, Office 2024, and Office Online Server to address this heap-based buffer overflow vulnerability.

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