Exploited· due 2026-04-28
CVE-2009-0238
Microsoft Office
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.
Exploitation status
- CISA has confirmed this is being exploited in the wild. That is an observation of real attacks, not a prediction.
- US federal civilian agencies are required to remediate it by 2026-04-28. That deadline does not bind private companies, but it is a reasonable benchmark for how urgently CISA views it.
Required action
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
CISA’s wording, unedited.
Scoring
- CVSS
- Not yet scored
Dates
- Published
- 2026-04-14
- Added to KEV
- 2026-04-14
- Remediation due
- 2026-04-28
- Sources
- CISA KEV