CVE-2009-1537
Microsoft DirectX NULL Byte Overwrite Vulnerability
Microsoft DirectX
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."
Exploitation status
CISA Known Exploited Vulnerabilities
Listed by CISA on 20 May 2026. US federal agencies were required to remediate it by 3 June 2026.
EPSS — exploitation probability
FIRST puts the probability of exploitation activity in the next 30 days at 51.2%, which is higher than 98.9% of all scored vulnerabilities. EPSS is a forecast of activity, not a measure of severity, and it is rescored daily.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Frequently asked questions
Is CVE-2009-1537 being exploited by ransomware groups?
No ransomware group in this database is currently recorded as exploiting CVE-2009-1537.
What does CVE-2009-1537 affect?
CVE-2009-1537 affects Microsoft DirectX. 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."
How severe is CVE-2009-1537?
CVE-2009-1537 is rated HIGH with a CVSS base score of 8.8. EPSS puts the probability of exploitation in the next 30 days at 51.2%, higher than 98.9% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 3 June 2026.
How should organisations respond to CVE-2009-1537?
Apply the vendor patch for Microsoft DirectX as the first priority, and treat any internet-facing instance as the most urgent. Because this vulnerability is associated with ransomware activity, also review whether the affected systems were reachable before patching, rather than assuming that patching alone closes the incident.