Microsoft Windows Media Foundation: Remote code execution (heap-based buffer overflow)
Summary
A heap-based buffer overflow in Windows Media Foundation, the multimedia framework used across Windows clients and servers, allows code execution over a network. The published CVSS 3.1 vector (9.8, Critical) indicates no authentication and no user interaction, but this is not yet verified against the MSRC advisory, and NVD is still awaiting analysis. Successful exploitation would give an attacker full control over the affected system.
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 and 22H2: builds before 10.0.19044.7846 and 10.0.19045.7846
- Windows 11 Version 23H2: builds before 10.0.22631.7711
- Windows 11 Version 24H2 and 25H2, and Windows 11 Version 26H2: builds before 10.0.26100.9974, 10.0.26200.9974 and 10.0.26300.9974
- Windows 11 Version 26H1: builds before 10.0.28000.3501
- Windows Server 2022: builds before 10.0.20348.5870
Fixed in
- Fixed in the builds that are not listed as affected above (the affected ranges end at the first fixed build). KB article numbers: Unknown.
Workaround
Unknown. No vendor mitigation was found. Check the MSRC advisory for any published workaround.
Exploitation
- No known exploitation at the time of research (no KEV listing, no public proof of concept found).
- CISA SSVC assessment: Exploitation none, Automatable yes, Technical Impact total.
Our recommendation
- Open the MSRC advisory and confirm the attack vector, privileges and user interaction requirements before setting the priority.
- Patch Windows clients and servers, including Server Core installations, in the next update cycle, starting with internet-facing and file-processing systems.
- Until patched, limit exposure to untrusted media files such as email attachments, downloads and file previews.
- Monitor NVD and CISA KEV for changes in status.
Information from Microsoft (Patch Tuesday November 2026)
- Severity (Microsoft)
- Important
- Impact
- Remote code execution – Microsoft Windows Media Foundation
- 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
- Microsoft Security Response Center: CVE-2026-96157 advisory msrc.microsoft.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 10 Nov 2026, 20:31.
Original description (NVD)
Heap-based buffer overflow in Microsoft Windows Media Foundation allows an unauthorized attacker to execute code over a network.
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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