Microsoft DirectX NULL Byte Overwrite Vulnerability

Added to KEV
2026-05-20
Federal due date
2026-06-03
Vendor
Microsoft
Product
DirectX
EPSS
98.0th percentile (score 0.530, as of 2026-06-08)
NVD CVSS v3.1
8.8 (HIGH)
Ransomware use
Unknown
Upstream
https://nvd.nist.gov/vuln/detail/CVE-2009-1537

CISA short description

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.

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.

NVD 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."

EPSS percentile is the FIRST.org exploit-probability ranking as of the date noted above; it moves daily. CVSS reflects NVD's analysis at time of publication.