Threats / Microsoft / CVE-2009-0238
CVE-2009-0238
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-06-22
Microsoft Office vulnerability
Microsoft Office Excel remote code execution via malformed object in specially crafted files, exploited in the wild.
Verdict
Today item — known-exploited.
A remote code execution vulnerability in Microsoft Office Excel allows attackers to achieve complete system compromise through user interaction with a malicious Excel file containing a malformed object.
01
Is it exploitable?
— the evidence, ranked above the scoreReported exploitation
3 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2026-04-14).
Probability (EPSS)
EPSS 0.43063 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Microsoft, Office. Confirm exact fixed builds in the vendor advisory.
Weakness (CWE)
Mapped to CWE-94 Code Injection — weakness family: Injection.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
02
Who’s exploiting it?
— attribution turns risk into urgencyAttribution not established
No confirmed (advisory-backed) threat-actor attribution is established for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.
03
Why it matters
— the attack path, told twice: adversary, then board1
Front door — unauthenticated access narrative 1
Attacker
I craft an Excel file with a malformed object designed to trigger unsafe code execution.
Business
Users remain unaware of the attack vector until the file is opened, creating a window of exposure.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I distribute the malicious file via email, file sharing, or web download to target users.
Business
Social engineering and supply chain distribution increase the likelihood of user interaction with the payload.
3
Lateral reach — past segmentation narrative 3
Attacker
When a user opens the file in Excel, the malformed object triggers arbitrary code execution with user privileges.
Business
The compromised system becomes a foothold for lateral movement, data exfiltration, or persistent access.
04
What to do
— defensible action- Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05