Microsoft Windows DirectMusic: Local code execution via heap-based buffer overflow
Summary
A heap-based buffer overflow in the Microsoft DirectMusic component of Windows allows an authorized local attacker to execute code. The attacker needs a low-privilege logon on the affected system and no user interaction is required. The CNA record rates the issue as High (CVSS 3.1 7.8), and the CISA SSVC assessment lists no exploitation and no automatable path.
Affected
- Windows 10 Version 1607 and Windows Server 2016 (including Server Core): builds before 10.0.14393.9688
- Windows 10 Version 1809 and Windows Server 2019 (including Server Core): builds before 10.0.17763.9487
- Windows 10 Version 21H2: builds before 10.0.19044.7846
- Windows 10 Version 22H2: builds before 10.0.19045.7846 (unverified, from a third-party mirror)
- Windows 11 Version 23H2: builds before 10.0.22631.7711 (unverified, from a third-party mirror)
- Windows 11 Version 24H2, 25H2, 26H1, 26H2 and Windows Server 2022: see the MSRC update guide for exact builds
Fixed in
- Install the November 2026 cumulative updates from Microsoft for the affected Windows versions.
- Exact fixed builds for Windows 10 22H2, Windows 11 and Windows Server are to be verified in the MSRC update guide.
Workaround
Unknown.
Exploitation
- No known exploitation in the wild at the time of writing.
- No public proof of concept found.
- Not listed in CISA KEV as far as checked.
Our recommendation
- Apply the November 2026 cumulative updates to all affected Windows systems, prioritising multi-user systems and terminal servers.
- Check whether Windows 10 systems are enrolled in Extended Security Updates, as unpatched systems will not receive this fix.
- Restrict local logon to trusted users and keep endpoint protection active.
- Verify the exact fixed builds in the MSRC update guide.
- Do not confuse this with CVE-2026-69491, a separate DirectMusic bug that is remotely exploitable.
Information from Microsoft (Patch Tuesday November 2026)
- Severity (Microsoft)
- Important
- Impact
- Remote code execution – Windows Microsoft DirectMusic
- Status on Patch Tuesday
- Neither exploited nor publicly disclosed
- Exploitability assessment
- Exploitation less likely
- Product family
- Windows, Windows ESU (Extended Security Updates)
- Updates (KB)
- KB5131291, KB5131085, KB5131096, KB5131090, KB5131087, KB5132061
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- CVE.org CNA record www.cve.org
- MSRC Security Update Guide msrc.microsoft.com
- Third-party mirror with build ranges www.strix.ai
- Related DirectMusic CVE-2026-69491 (different bug) vulners.com
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 11 Nov 2026, 03:05.
Original description (NVD)
Heap-based buffer overflow in Windows Microsoft DirectMusic allows an authorized attacker to execute code locally.
NVD references (1)
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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