Is CVE-2009-3129 being actively exploited?

Yes. CVE-2009-3129 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added on March 3, 2022.

What is the CVSS score for CVE-2009-3129?

CVE-2009-3129 has a CVSS 3.1 base score of 7.8 (HIGH).

CVE-2009-3129

HIGH · CVSS 7.8CISA KEV: actively exploitedEPSS 84.0%EU EUVD: exploited

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."

Key facts

CVSS score: 7.8 (v3.1)
Severity: HIGH
CVSS vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Weakness (CWE): CWE-787
EPSS score: 84.0% (100th percentile)
In CISA KEV: Yes, added March 3, 2022
In EU EUVD: Yes (EUVD-2009-3112)
Published: November 11, 2009
NVD last modified: June 16, 2026
Status: Analyzed

CISA Known Exploited Vulnerability

Microsoft Excel Featheader Record Memory Corruption Vulnerability

Added to the KEV catalog on March 3, 2022; federal remediation due March 24, 2022.

EU Vulnerability Database (EUVD)

This vulnerability is also tracked by ENISA as EUVD-2009-3112 in the EU Vulnerability Database. ENISA flags it as known exploited. Last updated in EUVD on October 22, 2025.

View on the EU Vulnerability Database

Affected products

microsoft / excel
microsoft / excel
microsoft / excel
microsoft / excel
microsoft / excel viewer
microsoft / excel viewer
microsoft / excel viewer
microsoft / office
microsoft / office
microsoft / open xml file format converter

References

http://archives.neohapsis.com/archives/bugtraq/2009-11/0080.html(Broken Link)
http://labs.idefense.com/intelligence/vulnerabilities/display.php?id=832(Broken Link)
http://osvdb.org/59860(Broken Link)
http://www.exploit-db.com/exploits/14706(Exploit, Third Party Advisory, VDB Entry)
http://www.securityfocus.com/bid/36945(Broken Link, Third Party Advisory, VDB Entry)
http://www.securitytracker.com/id?1023157(Broken Link, Third Party Advisory, VDB Entry)
http://www.us-cert.gov/cas/techalerts/TA09-314A.html(Third Party Advisory, US Government Resource)
http://www.zerodayinitiative.com/advisories/ZDI-09-083(Third Party Advisory, VDB Entry)
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2009/ms09-067(Patch, Vendor Advisory)
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A6521(Broken Link)
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2009-3129(US Government Resource)

Last updated September 17, 2026 · Source: NVD, CISA KEV, FIRST.org EPSS

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