SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2009-0238

Microsoft Office Remote Code Execution

KEVHIGH 8.8EPSS 43.2%

Does this matter?

Known to be exploited in the wild (CISA KEV, CISA remediation deadline 28 April 2026). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.

Description

Microsoft Office Excel 2000 SP3, 2002 SP3, 2003 SP3, and 2007 SP1; Excel Viewer 2003 Gold and SP3; Excel Viewer; Compatibility Pack for Word, Excel, and PowerPoint 2007 File Formats SP1; and Excel in Microsoft Office 2004 and 2008 for Mac allow remote attackers to execute arbitrary code via a crafted Excel document that triggers an access attempt on an invalid object, as exploited in the wild in February 2009 by Trojan.Mdropper.AC.

CVSS 3.1
8.8 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS
43.21% probability · 99th percentile
CISA KEV
Listed 14 April 2026 · due 28 April 2026
Weakness
CWE-94
Affected
microsoft/excel · microsoft/excel viewer · microsoft/office · microsoft/office compatibility pack · microsoft/office excel viewer
Source
secure@microsoft.com

CISA notes

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. https://learn.microsoft.com/en-us/security-updates/securitybulletins/2009/ms09-009 ; https://nvd.nist.gov/vuln/detail/CVE-2009-0238

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.