CVE-2010-0263: Microsoft Excel

High severity, CVSS 9.3. EPSS: 25.7% chance of exploitation in the next 30 days.

Microsoft Office Excel 2007 SP1 and SP2; Office 2008 for Mac; Open XML File Format Converter for Mac; Office Excel Viewer SP1 and SP2; Office Compatibility Pack for Word, Excel, and PowerPoint 2007 File Formats SP1 and SP2; and Office SharePoint Server 2007 SP1 and SP2 do not validate ZIP headers during decompression of Open XML (.XLSX) documents, which allows remote attackers to execute arbitrary code via a crafted document that triggers access to uninitialized memory locations, aka "Microsoft Office Excel XLSX File Parsing Code Execution Vulnerability."

Affected products

• Microsoft Excel: version 2002 only; version 2003 only; version 2007 only
• Microsoft Office: version 2004 only; version 2008 only
• Microsoft Office Compatibility Pack: version 2007 only
• Microsoft Office Excel Viewer: any version
• Microsoft Office SharePoint Server: version 2007 only
• Microsoft Open XML File Format Converter: any version

Published 2010-03-10. Last modified 2026-06-16.