Microsoft Windows Media Foundation: Heap overflow allows local privilege escalation
Summary
A heap-based buffer overflow in Microsoft Windows Media Foundation allows a locally authorized user to elevate their privileges. The attack requires local access and a low-privileged account, so it is not exposed over the network. An attacker would typically use it as a second step after gaining a foothold on the system. Microsoft rates the CVSS score at 7.8 (High).
Affected
- Windows 10 Version 1607 (builds before 10.0.14393.9688)
- Windows 10 Version 1809 (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)
- Windows 11 Version 23H2 (builds before 10.0.22631.7711)
- Windows 11 Version 24H2 (builds before 10.0.26100.9974)
- Windows 11 Version 25H2 (builds before 10.0.26200.9974)
- Windows 11 Version 26H1 (builds before 10.0.28000.3501)
- Windows 11 Version 26H2 (builds before 10.0.26300.9974)
- Windows Server 2016 (builds before 10.0.14393.9688)
- Windows Server 2019 (builds before 10.0.17763.9487)
- Windows Server 2022 (builds before 10.0.20348.5870)
- Third-party mirrors list differing build ranges for some products; verify against the MSRC advisory.
Fixed in
- Security updates released with the November 2026 cumulative updates, per the fixed build numbers listed above.
- Exact KB article numbers per product: Unknown. Check the MSRC advisory.
Workaround
Unknown. No vendor workaround or mitigation has been identified; patching is the expected fix.
Exploitation
- No exploitation in the wild known at publication.
- No public proof-of-concept known.
- CISA SSVC: exploitation none, automatable no, technical impact total.
Our recommendation
- Check the MSRC advisory and install the November 2026 cumulative update on all affected systems, prioritising servers and multi-user systems.
- Identify Windows 10 1607, 1809 and 21H2 systems and check whether they still receive security updates.
- Enforce least privilege, restrict local logons on shared systems and keep EDR active.
- Monitor the MSRC page for exploitation updates.
Information from Microsoft (Patch Tuesday November 2026)
- Severity (Microsoft)
- Important
- Impact
- Elevation of privilege – 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-2026-122168 advisory msrc.microsoft.com
- CVE Record CVE-2026-122168 (CVE.org) www.cve.org
- Strix.ai: CVE-2026-122168 (third-party mirror) www.strix.ai
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, 03:31.
Original description (NVD)
Heap-based buffer overflow in Microsoft Windows Media Foundation allows an authorized attacker to elevate privileges 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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