Is CVE-2009-0556 being actively exploited?

Yes. CVE-2009-0556 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added on January 7, 2026.

What is the CVSS score for CVE-2009-0556?

CVE-2009-0556 has a CVSS 3.1 base score of 8.8 (HIGH).

CVE-2009-0556

HIGH · CVSS 8.8CISA KEV: actively exploitedEPSS 67.3%EU EUVD: exploited

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."

Key facts

CVSS score: 8.8 (v3.1)
Severity: HIGH
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Weakness (CWE): CWE-94
EPSS score: 67.3% (99th percentile)
In CISA KEV: Yes, added January 7, 2026
In EU EUVD: Yes (EUVD-2009-0560)
Published: April 3, 2009
NVD last modified: June 16, 2026
Status: Analyzed

CISA Known Exploited Vulnerability

Microsoft Office PowerPoint Code Injection Vulnerability

Added to the KEV catalog on January 7, 2026; federal remediation due January 28, 2026.

EU Vulnerability Database (EUVD)

This vulnerability is also tracked by ENISA as EUVD-2009-0560 in the EU Vulnerability Database. ENISA flags it as known exploited. Last updated in EUVD on January 8, 2026.

View on the EU Vulnerability Database

Affected products

microsoft / office powerpoint
microsoft / powerpoint
microsoft / powerpoint
microsoft / powerpoint

References

http://blogs.technet.com/mmpc/archive/2009/04/02/new-0-day-exploits-using-powerpoint-files.aspx(Vendor Advisory)
http://blogs.technet.com/msrc/archive/2009/04/02/microsoft-security-advisory-969136.aspx(Vendor Advisory)
http://blogs.technet.com/srd/archive/2009/04/02/investigating-the-new-powerpoint-issue.aspx(Vendor Advisory)
http://osvdb.org/53182(Broken Link)
http://secunia.com/advisories/34572(Vendor Advisory)
http://www.kb.cert.org/vuls/id/627331(US Government Resource)
http://www.microsoft.com/technet/security/advisory/969136.mspx(Patch, Vendor Advisory)
http://www.securityfocus.com/archive/1/503453/100/0/threaded(Broken Link)
http://www.securityfocus.com/bid/34351(Broken Link)
http://www.securitytracker.com/id?1021967(Broken Link)
http://www.us-cert.gov/cas/techalerts/TA09-132A.html(US Government Resource)
http://www.vupen.com/english/advisories/2009/0915(Vendor Advisory)
http://www.vupen.com/english/advisories/2009/1290(Broken Link)
http://www.zerodayinitiative.com/advisories/ZDI-09-019(Third Party Advisory)
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2009/ms09-017(Vendor Advisory)
https://exchange.xforce.ibmcloud.com/vulnerabilities/49632(Third Party Advisory)
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A6204(Broken Link)
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A6279(Broken Link)
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2009-0556(US Government Resource)

Last updated September 17, 2026 · Source: NVD, CISA KEV, FIRST.org EPSS

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