Microsoft Office Remote Code Execution
Known exploited
CVE-2009-0238
Summary
Microsoft Office Excel contains a remote code execution vulnerability that could allow an attacker to take complete control of an affected system if a user opens a specially crafted Excel file that includes a malformed object.
Why it matters
CVE-2009-0238 is listed in CISA's Known Exploited Vulnerabilities catalog, confirming active exploitation in the wild. CISA remediation deadline: 2026-04-28. Treat remediation as urgent.
Operator check
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Sources
PatchBrief uses public sources. It does not scan environments, verify exposure, or replace vendor guidance.