Vulnerability record

CVE-2009-0557

Microsoft Office Object Record Corruption Vulnerability

HighExploitation confirmedCISA KEV

What should I do?

This vulnerability is in the CISA Known Exploited Vulnerabilities catalog: attackers are using it. If you run Office, fix it now.

CISA required action: Apply updates per vendor instructions.

US federal civilian agencies must remediate by Jun 22, 2022.

Patch status

Official fix available since Sep 30, 2026

Apply the vendor's update to every affected system. Check the fixed-in versions below where known.

Basis: NVD patch reference

Patch or advisory on docs.microsoft.com (opens in a new tab)

Description

Excel in Microsoft Office 2000 SP3, Office XP SP3, Office 2003 SP3, and Office 2004 and 2008 for Mac; Excel in 2007 Microsoft Office System SP1 and SP2; Open XML File Format Converter for Mac; Microsoft Office Excel Viewer 2003 SP3; Microsoft Office Excel Viewer; and Microsoft Office Compatibility Pack for Word, Excel, and PowerPoint 2007 File Formats SP1 and SP2 allow remote attackers to execute arbitrary code via a crafted Excel file with a malformed record object, aka "Object Record Corruption Vulnerability."

Source: NIST National Vulnerability Database. Official vulnerability data, reproduced as published.

Affected products

Products affected by this vulnerability, with versions and the source of each entry
Product	Vendor	Affected versions	Source
Office	Microsoft	2000; 2003; 2004; 2007; 2008; xp	KEV

Sources: KEV = CISA Known Exploited Vulnerabilities catalog.

Intelligence timeline

Developments from the last 30 days, newest first.

CVSS scoredUpdateKEVSep 30, 2026
CVE-2009-0557 scored CVSS 7.8: Microsoft Office, Microsoft Office Object Record Corruption Vulnerability
CISA lists this as exploited in the wild. Unpatched Office systems are exposed to active attacks now.
Basis: NIST National Vulnerability Database
Patch releasedUpdateKEVSep 30, 2026
Patch released for CVE-2009-0557: Microsoft Office, Microsoft Office Object Record Corruption Vulnerability
An official fix is now available for Microsoft Office. This vulnerability is being exploited, so apply it promptly.
Basis: NVD patch reference

1 earlier event is available with a subscription. See plans.

Coverage

We have not published a story about this vulnerability yet.

References

nvd.nist.gov https://nvd.nist.gov/vuln/detail/CVE-2009-0557
osvdb.org http://osvdb.org/54953
securityfocus.com http://www.securityfocus.com/bid/35241
securitytracker.com http://www.securitytracker.com/id?1022351
us-cert.gov http://www.us-cert.gov/cas/techalerts/TA09-160A.html
vupen.com http://www.vupen.com/english/advisories/2009/1540
docs.microsoft.com https://docs.microsoft.com/en-us/security-updates/securitybulletins/2009/ms09-021
oval.cisecurity.org https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A5564
cisa.gov https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2009-0557