How severe is CVE-2009-0238?

CVE-2009-0238 has a CVSS score of 8.8/10, rated HIGH. Immediate patching is strongly recommended.

Which products are affected by CVE-2009-0238?

Affected package information for CVE-2009-0238 is not yet fully mapped. Check the official advisory links for details.

How do I patch CVE-2009-0238?

No patch has shipped for CVE-2009-0238 yet — track the microsoft excel advisory for a fixed release and apply the workarounds below in the meantime.

How do I detect CVE-2009-0238 across my infrastructure?

Inventory every microsoft excel deployment and check each version against the affected-products list above. Because the exploit targets the running system rather than your application code, also watch for remote code execution at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.

How do I mitigate CVE-2009-0238 if there is no patch (or I can't update yet)?

Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.

How does O3 Security protect against CVE-2009-0238?

O3 detects and blocks CVE-2009-0238 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.

Is CVE-2009-0238 actively exploited in the wild?

Yes. There are 1 known exploit references for CVE-2009-0238, including 1 in-the-wild exploitation observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2009-0238?

CVE-2009-0238 has an EPSS (Exploit Prediction Scoring System) score of 43.1%, placing it in the 99th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score warrants monitoring and prompt remediation.

Is CVE-2009-0238 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2009-0238 (Microsoft Office Remote Code Execution) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2026-04-14. CISA required all US federal civilian agencies to remediate this vulnerability by 2026-04-28. The required action was: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

What type of vulnerability is CVE-2009-0238?

CVE-2009-0238 is classified as Code Injection (CWE-94). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

Which products and versions are affected by CVE-2009-0238?

CVE-2009-0238 affects microsoft excel (4 versions, e.g. 2000, 2002, 2003…); microsoft excel viewer; microsoft office (2 versions, e.g. 2004, 2008); microsoft office compatibility pack (1 version, e.g. 2007), and 1 more product(s). Check the affected-products list on this page against your deployed version to confirm exposure.

When was CVE-2009-0238 published, and has it been updated?

CVE-2009-0238 was published on February 25, 2009 and was last updated on June 16, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CISA KEV·Added 2026-04-14 — agencies required to remediate by 2026-04-28

CVE-2009-0238

HIGH

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…

Published

Feb 25, 2009

Updated

Jun 16, 2026

Affected

0 pkgs

Patched

None yet

Exploits

1 known

EPSS Exploitation Probability

via FIRST.org ↗

43.1%probability of exploitation in next 30 days

High Risk99th percentile0.00%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

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.

Affected Products

5 products · 10 configurations

Application

excelmicrosoft

4 versions

2000200220032007

Application

excel viewermicrosoft

all

Application

officemicrosoft

2 versions

20042008

Application

office compatibility packmicrosoft

1 version

2007

Application

office excel viewermicrosoft

1 version

2003

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

Microsoft Office Excel 2000 SP3, 2002 SP3, 2003 SP3, and 2007 SP1; Excel…

nvd.nist.govNVDOct 2018

Detection & mitigation playbook

Vendor / appliance

Detect
Inventory every microsoft excel deployment and check each version against the affected-products list above. Because the exploit targets the running system rather than your application code, also watch for remote code execution at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.
Remediation status
No patch has shipped for CVE-2009-0238 yet — track the microsoft excel advisory for a fixed release and apply the workarounds below in the meantime.
Mitigate without a patch
Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.
How O3 protects you
O3 detects and blocks CVE-2009-0238 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.

Tailored to CVE-2009-0238. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

O3 Security · Runtime Protection

Is CVE-2009-0238 being exploited in your environment?

O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2009-0238 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.

Protect my workloads How runtime protection works

CVE-2009-0238

EPSS Exploitation Probability

Description

Affected Products

Detection & mitigation playbook

Detect

Remediation status

Mitigate without a patch

How O3 protects you

Frequently Asked Questions

Is CVE-2009-0238 being exploited in your environment?