How severe is CVE-2009-0557?

CVE-2009-0557 has a CVSS score of 7.8/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2009-0557?

Affected package information for CVE-2009-0557 is not yet fully mapped. Check the official advisory links for details.

How do I fix CVE-2009-0557?

No fixed version has been published for CVE-2009-0557 yet. Monitor the advisory for updates, apply mitigations recommended by the vendor, and use O3 Security to track when a fix becomes available in your stack.

Is CVE-2009-0557 actively exploited in the wild?

Yes. There are 1 known exploit references for CVE-2009-0557, including 1 in-the-wild exploitation observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2009-0557?

CVE-2009-0557 has an EPSS (Exploit Prediction Scoring System) score of 86.4%, placing it in the 99th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. A score above 50% indicates significantly elevated exploitation risk — immediate patching is strongly recommended.

Is CVE-2009-0557 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2009-0557 (Microsoft Office Object Record Corruption Vulnerability) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2022-06-08. CISA required all US federal civilian agencies to remediate this vulnerability by 2022-06-22. The required action was: Apply updates per vendor instructions. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

What type of vulnerability is CVE-2009-0557?

CVE-2009-0557 is classified as Code Injection (CWE-94). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

Which products and versions are affected by CVE-2009-0557?

CVE-2009-0557 affects microsoft office (6 versions, e.g. 2000, 2003, 2004…); microsoft office compatibility pack (1 version, e.g. 2007); microsoft office excel viewer (1 version, e.g. 2003); microsoft office sharepoint server (1 version, e.g. 2007), and 1 more product(s). Check the affected-products list on this page against your deployed version to confirm exposure.

When was CVE-2009-0557 published, and has it been updated?

CVE-2009-0557 was published on June 10, 2009 and was last updated on April 22, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CISA KEV·Added 2022-06-08 — agencies required to remediate by 2022-06-22

CVE-2009-0557

HIGH

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…

Published

Jun 10, 2009

Updated

Apr 22, 2026

Affected

0 pkgs

Patched

None yet

Exploits

1 known

EPSS Exploitation Probability

via FIRST.org ↗

86.4%probability of exploitation in next 30 days

Very High Risk99th percentile0.00%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

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."

Affected Products

5 products · 14 configurations

Application

officemicrosoft

6 versions

20002003200420072008xp

Application

office compatibility packmicrosoft

1 version

2007

Application

office excel viewermicrosoft

1 version

2003

Application

office sharepoint servermicrosoft

1 version

2007

Application

open xml file format convertermicrosoft

all

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

Excel in Microsoft Office 2000 SP3, Office XP SP3, Office 2003 SP3, and …

cisa.govCISAJun 2022

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2009-0557 in your stack?

O3 detects CVE-2009-0557 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my stack How O3 SCA works

CVSS Score

7.8/10

CVSS v3 base score

Vector breakdown

AV:Attack Vector

Local

AC:Attack Complexity

Low

PR:Privileges Required

None

UI:User Interaction

Required

S:Scope

Unchanged

C:Confidentiality

High

I:Integrity

High

A:Availability

High

Raw vector

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

CWE Classification

CWE-94Code Injection

Weaponization

No known public exploit tooling found.

Timeline

Disclosed

Jun 10, 2009

KEV added

Jun 8, 2022

First exploit

Jun 8, 2022

Last updated

Apr 22, 2026

Identifiers

CVE-2009-0557

References

Advisorysecurityfocus.com Advisorysecuritytracker.com Advisoryus-cert.gov Advisorysecurityfocus.com Advisorysecuritytracker.com Advisoryus-cert.gov Fixdocs.microsoft.com Fixdocs.microsoft.com Webosvdb.org Webvupen.com Weboval.cisecurity.org Webosvdb.org Webvupen.com Weboval.cisecurity.org Webcisa.gov

Data from OSV.dev, enriched by O3 Security. Refreshed hourly.