Microsoft DirectX NULL Byte Overwrite Vulnerability

Date May 20, 2026
Type KEV
Signal Known exploited
Vendor / Product Microsoft ยท DirectX
CVE CVE-2009-1537
Known exploited CVE-2009-1537

Summary

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.

Why it matters

CVE-2009-1537 is listed in CISA's Known Exploited Vulnerabilities catalog, confirming active exploitation in the wild. CISA remediation deadline: 2026-06-03. Treat remediation as urgent.

Operator check

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Sources

PatchBrief uses public sources. It does not scan environments, verify exposure, or replace vendor guidance.