CVE-2009-3129: Microsoft Excel Featheader Record Memory Corruption Vulnerability

High severity, CVSS 7.8. Actively exploited: in CISA KEV since 2022-03-03. EPSS: 84% chance of exploitation in the next 30 days.

Microsoft Office Excel 2002 SP3, 2003 SP3, and 2007 SP1 and SP2; Office 2004 and 2008 for Mac; Open XML File Format Converter for Mac; Office Excel Viewer 2003 SP3; Office Excel Viewer SP1 and SP2; and Office Compatibility Pack for Word, Excel, and PowerPoint 2007 File Formats SP1 and SP2 allows remote attackers to execute arbitrary code via a spreadsheet with a FEATHEADER record containing an invalid cbHdrData size element that affects a pointer offset, aka "Excel Featheader Record Memory Corruption Vulnerability."

Affected products

• Microsoft Excel: version 2002 only; version 2003 only; version 2007 only
• Microsoft Excel Viewer: affected versions not specified; version 2003 only
• Microsoft Office: version 2004 only; version 2008 only
• Microsoft Open XML File Format Converter: any version

Published 2009-11-11. Last modified 2026-06-16.