Microsoft Windows Filtering Platform: Use after free allows local privilege escalation

Summary

A use-after-free flaw (CWE-416) in the Windows Filtering Platform (WFP), the network-filtering framework built into Windows, allows an authorized local user to elevate privileges. The CVSS 3.1 base score is 6.4 (Medium), and the vector requires local access, high attack complexity and high privileges. An attacker needs an existing foothold on the system, for example through phishing or a compromised low-privilege account. Microsoft has fixed the issue in its November 2026 security updates.

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
• Windows Server 2025: Unknown.

Fixed in

• Windows 10 Version 1607 / Windows Server 2016: 10.0.14393.9688 or later
• Windows 10 Version 1809 / Windows Server 2019: 10.0.17763.9487 or later
• Windows 10 Version 21H2: 10.0.19044.7846 or later
• Windows 10 Version 22H2: 10.0.19045.7846 or later
• Windows 11 Version 23H2: 10.0.22631.7711 or later
• Windows 11 Version 24H2: 10.0.26100.9974 or later
• Windows 11 Version 25H2: 10.0.26200.9974 or later
• Windows 11 Version 26H1: 10.0.28000.3501 or later
• Windows 11 Version 26H2: 10.0.26300.9974 or later
• Windows Server 2022: 10.0.20348.5870 or later
• Windows Server 2025: Unknown; verify the build in the MSRC advisory.

Workaround

Unknown. No vendor workaround has been confirmed. Install the November 2026 security update.

Exploitation

• No known exploitation in the wild.
• CISA SSVC: Exploitation none, Automatable no, Technical Impact total.
• Rapid7: Exploitation Less Likely, not publicly disclosed.
• No public proof-of-concept exploit is known.

Our recommendation

• Install the November 2026 cumulative update on all affected Windows 10, 11 and Server systems, starting with shared servers, terminal servers and systems with many users.
• Verify the fixed build numbers against the MSRC advisory before rollout, especially for Windows Server 2025.
• Identify and replace or update out-of-support Windows versions still in use.
• Limit local logon rights and local accounts on servers and workstations to reduce the risk of an attacker gaining a foothold.
• Monitor for unusual privilege changes and new local administrator accounts.

Public exploits iAttack code is publicly available (PoC on GitHub, Metasploit or Exploit-DB).

PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.

Research sources

• CVE Record CVE-2026-88215 www.cve.org
• Microsoft Security Update Guide CVE-2026-88215 msrc.microsoft.com
• Rapid7 Patch Tuesday November 2026 www.rapid7.com
• Senserva KB5131080 senserva.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, 13:47.