CVE-2009-0557VulnerabilityPublished 06/08/2022Updated 10/24/2026

CVE-2009-0557: Microsoft Office Object Record Corruption Vulnerability

Affects Microsoft OfficeSource CISA KEV

Severity

High

No CVSS score published yet

Exploitation: Actively exploited – in CISA KEV since 06/08/2022
KEV deadline: 06/22/2022
EPSS: 52.8% chance of exploitation in 30 days – higher than 98% of CVEs

What to do

CISA required action

Apply updates per vendor instructions.

nvd.nist.gov/vuln/detail/CVE-2009-0557 (opens in a new tab)

Description

Microsoft Office contains a vulnerability in its handling of object records within Excel files. This flaw allows remote attackers to execute arbitrary code by crafting a malicious Excel file with a malformed record object. The vulnerability has been exploited in the wild, indicating active use by attackers. No specific affected versions or patch information is provided in the available data.

Summary

CVE-2009-0557 is a vulnerability in Microsoft Office where an object record corruption in Excel files can be exploited by remote attackers to execute arbitrary code. The attack vector involves a specially crafted Excel file containing malformed record objects. This vulnerability has been confirmed to be exploited in the wild. No detailed version or patch information is available from the provided data.

Impact

Successful exploitation allows remote code execution on the affected system, potentially leading to full compromise of the user's environment. The presence of known exploitation in the wild increases the risk to users of vulnerable Microsoft Office versions.

Mitigation

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Users should refer to Microsoft's official security advisories for updates and apply any available patches promptly. Until a patch is confirmed, exercising caution when opening Excel files from untrusted sources is recommended.

Weaknesses

CWE-94Code Injection (opens in a new tab)

What to do

Description

AnalysisAI-generated, updated 10/24/2026, 11:51:25 UTC

Weaknesses

References

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