What is CVE-2009-0238?

CVE-2009-0238 is Microsoft Office Remote Code Execution. The supplied enrichment data classifies it as Remote Code Exec mapped to CWE-94 Code Injection.

Which versions are affected?

Affected product and version evidence is listed in the product table above. Current public advisories should be checked for exact version scope before patch targeting is finalized.

Is there active exploitation?

Yes: CISA KEV signal present. If exploitation is not confirmed from current sources, teams should document that status and continue monitoring KEV, vendor, and telemetry updates.

Is there a public exploit?

5 public PoC repositories reported; 0 marked weaponized in current dataset. Public exploit or PoC availability should raise triage priority, especially for exposed or business-critical systems.

How can defenders detect it?

Start with web/proxy/WAF logs, application logs, network IDS/IPS, EDR process telemetry, host service logs where available. Look for vulnerability-class behavior, product errors, suspicious authentication events, exploit probes, and abnormal process activity based only on evidence that applies to the affected product.

How should teams prioritize it?

Prioritize CVE-2009-0238 using CVSS 9.3, EPSS 43%, KEV status, public PoC status, and asset exposure. Internet-facing, privileged, or business-critical deployments should be handled first.

Are workarounds available?

The supplied mitigation guidance says to apply vendor patches and restrict external exposure until fixed. Fixed-version evidence is listed in the mitigation section above.

Which threat actors are linked publicly?

No public threat actor linkage is confirmed from current sources. Do not attribute exploitation to a threat actor unless the source evidence explicitly supports that linkage.

What should be done in the next 24 hours?

Identify exposed assets running affected vendor/product/version combinations. Treat as emergency remediation because CISA KEV status is present. Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class. Open remediation tickets with affected assets, owners, evidence status, and detection coverage so decisions are traceable.

CISA KEVhighRemote Code Execpublic exploit

CVE-2009-0238

Microsoft Office Remote Code Execution

Q: Is it in CISA KEV?

Yes. The supplied enrichment data lists CVE-2009-0238 in CISA KEV with 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.. KEV status should be monitored because it can change after initial disclosure or after exploitation becomes publicly confirmed.

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.

Published Feb 25, 2009Updated Jun 16, 2026Sources: NVD, Microsoft (CNA), CISA, FIRST EPSS, GitHub, GitHub Security Advisory

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.

Exploitation

Confirmed

CISA KEV, listed Apr 14, 2026

EPSS

43%

ahead of 99% of scored CVEs

Affects

Microsoft

Office

CVSS base

9.3

high · 2 sources

CISA SSVC assessment

Three decision points CISA publishes for the CVEs it assesses · SSVC 2.0.3. A stakeholder decision, not a severity score.

CISA

Exploitation

Active

none · proof-of-concept · active

Automatable

can an attacker script all four kill-chain steps

Technical impact

Total

partial · total control of the vulnerable component

Remediation

The vendor's own words where we have them.

Upgrade Office to a fixed release. Apply vendor patches per advisory and restrict external exposure of the affected component until patched.

CISA 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.

Federal deadline Apr 28, 2026 — passed 115 days ago

First 24 hours

Ordered from the record's own fields — exposure first, because you cannot patch what you have not found.

Identify exposed assets running affected vendor/product/version combinations.
Treat as emergency remediation because CISA KEV status is present.
Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class.

Affected scope

Vendor, product and version as the advisories word them.

Vendor	Product	Versions	Status
Microsoft	Office	—	Vulnerable

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Availability

Changed

Confidentiality

Changed

Integrity

Changed

Attack Complexity

Attack Vector

Network

Every base score collected

Sources score independently and disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Source
8.8	CVSS 3.1	high	2.8	5.9	CNA, GHSA
9.3	CVSS 2.0	high	8.6	10	NVD

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Weakness & attack patterns

CWE-94Code Injection

Inferred from the weakness class — not observed against this CVE.

CAPEC-242 · Code InjectionCAPEC-35 · Leverage Executable Code in Non-Executable Files

T1027.006Obfuscated Files or Information: HTML Smuggling
T1027.009Obfuscated Files or Information: Embedded Payloads
T1564.009Hide Artifacts: Resource Forking

CISA KEV details

CISA lists a CVE here once it has evidence of exploitation against real targets.

CISAThat month →

Listed

Apr 14, 2026

Federal deadline

Apr 28, 2026

passed 115 days ago

Ransomware use

Unknown

CISA records ransomware use only for campaigns it has confirmed, so “Unknown” means unrecorded, not ruled out. The deadline binds US federal agencies; for everyone else it is a date to argue against.

Public exploit

Capability, not use: code existing is a different claim from anyone running it.

Repositories

Detection

Read off the CVSS vector and the weakness class. Starting points, not rules we have tested.

Prioritize edge telemetry for network-reachable Office.
Monitor for scanner or exploit-pattern traffic after 5 public PoC repositories were reported.

web/proxy/WAF logsapplication logsnetwork IDS/IPSEDR process telemetryhost service logs

Timeline

What happened to this CVE, newest first — with the readings a source repeats on a schedule counted underneath rather than listed.

2026
Added · CVSS 3.1 9.3 (AV:N)
Jun 16, 2026 · NVD
Added to CISA KEV catalog
Apr 14, 2026 · CISA
2022
Added · GHSA-qw7j-w352-g8m7 published (high)
May 2, 2022 · GitHub Security Advisory
2009
Initial · CVE published
Feb 25, 2009 · NVD

References

15 on the record

blogs.zdnet.com/security/?p=2658
Broken Link
isc.sans.org/diary.html?storyid=5923
Press/Media Coverage
securitytracker.com/id?1021744
Broken Link
www.microsoft.com/technet/security/advisory/968272.mspx
Vendor Advisory
www.securityfocus.com/bid/33870
Broken Link
www.symantec.com/business/security_response/writeup.jsp?docid=2009-022310-4202-99
Broken Link
www.us-cert.gov/cas/techalerts/TA09-104A.html
US Government Resource
www.vupen.com/english/advisories/2009/1023
Broken Link

Elsewhere on this site

Microsoftevery CVE for this vendor
April 2026what else CISA listed
Remote Code Execsame class
CWE-94other pages naming this weakness

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record1

What should defenders know first?

CVE-2009-0238 is Microsoft Office Remote Code Execution, a high vulnerability affecting Office from Microsoft. The current evidence lists it in CISA KEV, and the exploit status is: Yes: CISA KEV signal present. Public exploit evidence is: 5 public PoC repositories reported; 0 marked weaponized in current dataset. The affected-version evidence is listed in the key facts and affected products tables. Defenders should first verify whether exposed or business-critical assets run those versions, then apply vendor patches or mitigations, restrict reachable attack surface, and preserve logs for detection review. CVSS 9.3 describes technical severity, while EPSS 43% helps estimate near-term exploit likelihood; neither replaces asset context. Unknown fields should remain explicit in tickets, and threat actor, IOC, victimology, or payload claims should not be added unless a cited source supports them. Monitor CISA KEV, vendor advisories, NVD changes, public PoC repositories, and internal telemetry for update triggers.