Executive Summary

CVE-2020-0901 is a remote code execution flaw in Microsoft Excel that mishandles in‑memory objects, allowing an attacker to run arbitrary code as the current user. If the user has administrative rights, the attacker can gain full system control, install software, alter or delete data, and create privileged accounts. Exploitation requires a user to open a specially crafted Excel file, typically delivered via phishing or malicious web content. The issue is mitigated by Microsoft’s patch correcting memory handling.

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Authoritative CVE Metadata - CVSS Base Score: 9.8 (CRITICAL) - Published: 2020-05-21T23:15:11.210 - Last Modified: 2026-08-19T17:17:07.190

Original Description: A remote code execution vulnerability exists in Microsoft Excel software when the software fails to properly handle objects in memory. An attacker who successfully exploited the vulnerability could run arbitrary code in the context of the current user. If the current user is logged on with administrative user rights, an attacker could take control of the affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. Users whose accounts are configured to have fewer user rights on the system could be less impacted than users who operate with administrative user rights. Exploitation of the vulnerability requires that a user open a specially crafted file with an affected version of Microsoft Excel. In an email attack scenario, an attacker could exploit the vulnerability by sending the specially crafted file to the user and convincing the user to open the file. In a web-based attack scenario, an attacker could host a website (or leverage a compromised website that accepts or hosts user-provided content) containing a specially crafted file designed to exploit the vulnerability. An attacker would have no way to force users to visit the website. Instead, an attacker would have to convince users to click a link, typically by way of an enticement in an email or instant message, and then convince them to open the specially crafted file. The security update addresses the vulnerability by correcting how Microsoft Excel handles objects in memory.

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