Microsoft DirectX NULL Byte Overwrite Vulnerability

[ Why it matters ]Priority signals

• Exploited in the wild: on CISA's Known Exploited Vulnerabilities list since 2026-05-20
• EPSS: 51% chance of exploitation in the next 30 days (higher than 99% of CVEs)

[ Description ]Official description

Unspecified vulnerability in the QuickTime Movie Parser Filter in quartz.dll in DirectShow in Microsoft DirectX 7.0 through 9.0c on Windows 2000 SP4, Windows XP SP2 and SP3, and Windows Server 2003 SP2 allows remote attackers to execute arbitrary code via a crafted QuickTime media file, as exploited in the wild in May 2009, aka "DirectX NULL Byte Overwrite Vulnerability."

CISA: Microsoft DirectX contains a NULL byte overwrite vulnerability in the QuickTime Movie Parser Filter in quartz.dll in DirectShow which could allow remote attackers to execute arbitrary code via a crafted QuickTime media file.

[ Fixes ]Fixes and patches

CISA required action (US federal deadline 3 Jun 2026): Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

• Patch on microsoft.comVendor patch or bulletin · NVD · Reference tagged 'Patch' by NVD

[ References ]References

• blogs.technet.com/msrc/archive/2009/05/28/microsoft-security-advisory-971778-vulnerabil…Vendor Advisory
• blogs.technet.com/srd/archive/2009/05/28/new-vulnerability-in-quicktime-parsing.aspxVendor Advisory
• isc.sans.org/diary.htmlNot Applicable
• osvdb.org/54797Broken Link
• secunia.com/advisories/35268Vendor Advisory
• www.microsoft.com/technet/security/advisory/971778.mspxPatchVendor Advisory
• www.securityfocus.com/bid/35139Broken Link
• www.securitytracker.com/idBroken Link
• www.us-cert.gov/cas/techalerts/TA09-195A.htmlUS Government Resource
• www.vupen.com/english/advisories/2009/1445Vendor Advisory
• www.vupen.com/english/advisories/2009/1886Vendor Advisory
• docs.microsoft.com/en-us/security-updates/securitybulletins/2009/ms09-028Vendor Advisory
• oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A6237Broken Link
• www.cisa.gov/known-exploited-vulnerabilities-catalogUS Government Resource