Threat Intelligence / CVE / CVE-2009-1537

CVE-2009-1537 — Microsoft Directx

CISA KEVRansomware
CVSS v3.1 8.8 (HIGH) · EPSS 53.0% (higher than 98.0% of all scored CVEs) · Priority 10/10 · Published 2009-05-29

As of 2026-05-21, CVE-2009-1537 is a HIGH-severity vulnerability in Microsoft Directx, CVSS v3.1 8.8, EPSS 53.0% (98.0th percentile). It is listed in the CISA Known Exploited Vulnerabilities catalog (added 2026-05-20), with a US federal remediation deadline of 2026-06-03, and CISA links it to known ransomware campaigns. Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2009-1537, most recently “CISA KEV Catalog Adds Seven Vulnerabilities (May 20, 2026) — Microsoft Defender CVE-2026-41091 (EoP) and CVE-2026-45498 (DoS) Headline Active Exploitation Batch”.

Last updated: 2026-05-21

What is CVE-2009-1537?

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."

The record classifies CVE-2009-1537 under weakness class CWE-158. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs a user to take an action first, and has high impact on confidentiality, integrity, availability. 5 affected-product entries are recorded, across 1 vendor, listed below. The identifier was first published 6315 days ago.

Severity and exploitation probability

CVSS v3.1 base score
8.8 — HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS (FIRST)
53.0% probability of exploitation in the next 30 days, higher than 98.0% of all scored CVEs
CISA KEV
Listed since 2026-05-20, federal remediation deadline 2026-06-03 — used in known ransomware campaigns
Threadlinqs priority
10/10 — CISA lists it as used in ransomware, which Threadlinqs scores at the maximum
Published
2009-05-29, last modified 2026-05-21

Is CVE-2009-1537 being exploited?

CISA added CVE-2009-1537 to the Known Exploited Vulnerabilities catalog on 2026-05-20, which means the agency holds evidence of exploitation in the wild; US federal civilian agencies had to remediate it by 2026-06-03 under BOD 22-01. CISA flags the vulnerability as one used in known ransomware campaigns. It currently carries a trending score of 40 in the Threadlinqs vulnerability feed.

Affected products and versions

How to fix CVE-2009-1537

The record marks a vendor fix as available for CVE-2009-1537. Patch reference: http://www.microsoft.com/technet/security/advisory/971778.mspx. Vendor advisory: http://blogs.technet.com/msrc/archive/2009/05/28/microsoft-security-advisory-971778-vulnerability-in-microsoft-directshow-released.aspx. Because CVE-2009-1537 is KEV-listed, US federal civilian agencies were required to apply the vendor fix, or stop using the product, by 2026-06-03. Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.

Threat activity tracking CVE-2009-1537

1 tracked threat in the Threadlinqs corpus references CVE-2009-1537, either in the campaign’s CVE list or as an indicator on the campaign record.

Sources

Seeded from cveorg and not yet processed by the Threadlinqs enrichment pipeline, so blank CVSS, EPSS or KEV fields above mean NOT MEASURED rather than measured-absent.

Full detection coverage & IOCs for threats exploiting CVE-2009-1537 are available via the Threadlinqs MCP server (Purple tier). View plans →

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