A critical untrusted pointer dereference vulnerability in Microsoft Office Excel poses a severe risk of local code execution for users of affected software.

This flaw involves an untrusted pointer dereference (CWE-822) within Microsoft Excel. The vulnerability requires user interaction, such as opening a maliciously crafted file, to trigger the execution of code in the local environment.

The vulnerability carries a CVSS score of 7.8, reflecting its potential for total impact on confidentiality, integrity, and availability if exploited. Successful exploitation could allow an attacker to gain full control over the local workstation, leading to unauthorized data access, the installation of malicious software, and potential lateral movement within the corporate network.

Immediate Action: Organizations must apply the latest security updates provided by Microsoft via the official update guide at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-62556.

Proactive Monitoring: Security teams should monitor endpoint security logs for suspicious Excel process activity, specifically focusing on unexpected child processes or abnormal memory access patterns.

Compensating Controls: Ensure that macro security settings are configured to disable unsigned or untrusted macros and utilize endpoint protection software to scan incoming files for malicious signatures.

Public Exploit Available: Unknown

Given the potential for complete system compromise, organizations should prioritize patching all instances of the affected Microsoft Office products. IT administrators should verify that automatic updates are enabled or push the relevant security patches through centralized management tools to ensure full coverage across the enterprise.