---
title: "CVE-2009-0556: Microsoft Office PowerPoint Code Injection Vulnerability"
url: https://erroneo.us/security/cve/CVE-2009-0556/
description: "CVE-2009-0556 (Microsoft Office): Exploited in the wild (CISA KEV). Microsoft Office PowerPoint 2000 SP3, 2002 SP3, and 2003 SP3, and PowerPoint in…"
type: vulnerability-record
section: "Security Digest"
date_published: 2009-04-03
date_modified: 2026-01-08
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2009-0556"
kev: true
cvss: 8.8
epss: 0.67312
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2009-0556: Microsoft Office PowerPoint Code Injection Vulnerability

**Signal:** Exploited: patch now if you run it. CISA has confirmed exploitation in the wild. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- Yes, if you run Microsoft Office. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2026-01-07, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2026-01-28 ; treat that as the outer limit, not the target.
- EPSS 67.3% , percentile 99: FIRST’s model estimates a 67.3% chance of exploitation activity in the next 30 days, higher than 99% of all scored CVEs (very high). EPSS is a probability, not a verdict.
- Needs a user to click or open something. Phishing makes that realistic, but it is not wormable.

## What it is

Microsoft Office PowerPoint 2000 SP3, 2002 SP3, and 2003 SP3, and PowerPoint in Microsoft Office 2004 for Mac, allows remote attackers to execute arbitrary code via a PowerPoint file with an OutlineTextRefAtom containing an an invalid index value that triggers memory corruption, as exploited in the wild in April 2009 by Exploit:Win32/Apptom.gen, aka "Memory Corruption Vulnerability."

## Affected products (CVE record)

- n/a n/a: see advisory

## Severity

- CISA-ADP CVSS 3.1: 8.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H`

## Exploitation

- CISA KEV: added 2026-01-07; federal due date 2026-01-28. Known ransomware use: Unknown.
- 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.
- CISA SSVC assessment: exploitation active , automatable no , technical impact total .
- FIRST EPSS (model of 2026-10-21): 67.31% probability of exploitation activity in the next 30 days; percentile 99.

## Sources

- [MS09-017](https://docs.microsoft.com/en-us/security-updates/securitybulletins/2009/ms09-017)
- [Listed in CISA KEV notes (learn.microsoft.com)](https://learn.microsoft.com/en-us/security-updates/securitybulletins/2009/ms09-017)
- [CVE.org record CVE-2009-0556](https://www.cve.org/CVERecord?id=CVE-2009-0556)
- [NVD entry CVE-2009-0556](https://nvd.nist.gov/vuln/detail/CVE-2009-0556)
- [CISA Known Exploited Vulnerabilities catalog entry](https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2009-0556)
- [zerodayinitiative.com](http://www.zerodayinitiative.com/advisories/ZDI-09-019)
- [blogs.technet.com](http://blogs.technet.com/mmpc/archive/2009/04/02/new-0-day-exploits-using-powerpoint-files.aspx)
- [ADV-2009-1290](http://www.vupen.com/english/advisories/2009/1290)
- [53182](http://osvdb.org/53182)
- [powerpoint-unspecified-code-execution(49632)](https://exchange.xforce.ibmcloud.com/vulnerabilities/49632)
- [34351](http://www.securityfocus.com/bid/34351)
- [ADV-2009-0915](http://www.vupen.com/english/advisories/2009/0915)
- [blogs.technet.com](http://blogs.technet.com/msrc/archive/2009/04/02/microsoft-security-advisory-969136.aspx)
- [blogs.technet.com](http://blogs.technet.com/srd/archive/2009/04/02/investigating-the-new-powerpoint-issue.aspx)
- [oval:org.mitre.oval:def:6279](https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A6279)
- [34572](http://secunia.com/advisories/34572)
- [1021967](http://www.securitytracker.com/id?1021967)
- [TA09-132A](http://www.us-cert.gov/cas/techalerts/TA09-132A.html)
- [microsoft.com](http://www.microsoft.com/technet/security/advisory/969136.mspx)
- [VU#627331](http://www.kb.cert.org/vuls/id/627331)
- [20090512 ZDI-09-019: Microsoft Office PowerPoint OutlineTextRefAtom Parsing Memory Corruption Vulnerability](http://www.securityfocus.com/archive/1/503453/100/0/threaded)
- [oval:org.mitre.oval:def:6204](https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A6204)

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Source page: https://erroneo.us/security/cve/CVE-2009-0556/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt