Microsoft Windows: Use-after-free in Link Layer Topology Discovery Protocol
Summary
A use-after-free vulnerability in the Windows Link Layer Topology Discovery Protocol (LLTD) allows an unauthorized attacker to execute code. The attacker must be on the same local network segment, and exploitation is rated as high complexity. No privileges or user interaction are required. Exploitation is not known, and CISA SSVC rates the issue as not automatable.
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
- 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 2022: builds before 10.0.20348.5870
Fixed in
- Install the Microsoft November 2026 cumulative update for your build. The fixed builds are the versions listed above as the upper limit, or later.
- KB numbers: Unknown. Check the MSRC advisory.
Workaround
- No vendor workaround is listed in the sources. Check the MSRC advisory for mitigations.
- Restrict Layer 2 access: isolate guest Wi-Fi, use VLANs and port security, and limit who can join the LAN segment.
Exploitation
- Exploitation in the wild: no evidence found.
- Public exploit code: none found.
- CISA SSVC: exploitation none, not automatable, total technical impact.
Our recommendation
- Install the November 2026 cumulative update on affected systems, starting with the oldest builds (Windows 10 1607, 1809, 21H2, 22H2).
- Restrict Layer 2 access in flat networks, shared offices and guest Wi-Fi.
- Verify the fixed builds against the MSRC advisory before rollout.
Information from Microsoft (Patch Tuesday November 2026)
- Severity (Microsoft)
- Important
- Impact
- Remote code execution – Windows Link Layer Topology Discovery Protocol
- 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 Record CVE-2026-116706 (CVE Program) www.cve.org
- MSRC Security Update Guide CVE-2026-116706 msrc.microsoft.com
- Strix CVE-2026-116706 (metadata and KEV status) www.strix.ai
- Link Layer Topology Discovery (Wikipedia) en.wikipedia.org
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, 05:46.
Original description (NVD)
Use after free in Windows Link Layer Topology Discovery Protocol allows an unauthorized attacker to execute code over an adjacent 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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