CVE-2026-102856

Summary

A heap-based buffer overflow in Microsoft Office Visio allows remote attackers to execute arbitrary code when processing specially crafted Visio files. This vulnerability could enable attackers to gain full control over affected systems.

Exploitability

Exploitation requires user interaction via opening a malicious Visio file, making it moderately difficult but achievable through social engineering or phishing campaigns.

Blast radius

If exploited, this vulnerability could compromise thousands of Office 365 and desktop Office users who frequently open Visio files, potentially leading to widespread system compromise.

Detection

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

Prioritized remediation

Deploy the Microsoft security update KB5042879 immediately to all affected systems running Office 2021 or Office 2024.

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