CVE-2026-83891

Summary

A stack-based buffer overflow in Microsoft Word allows remote attackers to execute arbitrary code when processing maliciously crafted documents over a network. This vulnerability could enable attackers to gain full control of affected systems without requiring user interaction.

Exploitability

Exploitation is moderately difficult as it requires crafting a malicious Word document and tricking users into opening it, but the attack surface is large since Office is widely used in enterprise environments.

Blast radius

The vulnerability could impact thousands of endpoints across an organization, potentially leading to full system compromise and lateral movement throughout the network.

Detection

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

Prioritized remediation

Deploy Microsoft Security Update KB5042813 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.