Windows Client for NFS: Use-after-free allowing privilege escalation

Summary

A use-after-free vulnerability (CWE-416) in the Windows Client for NFS component allows an unauthorized attacker to elevate privileges over the network. The attack complexity is high and no privileges or user interaction are required, according to the CVSS vector (8.1, High). The risk mainly concerns hosts that have the NFS client feature enabled and can reach a hostile or compromised NFS server.

Affected

• Windows 10 Version 1607 (10.0.14393.0 to before 10.0.14393.9688)
• Windows 10 Version 1809 (10.0.17763.0 to before 10.0.17763.9487)
• Windows 10 Version 21H2 (10.0.19044.0 to before 10.0.19044.7846)
• Windows 10 Version 22H2 (10.0.19045.0 to before 10.0.19045.7846)
• Windows 11 Version 23H2 (10.0.22631.0 to before 10.0.22631.7711)
• Windows 11 Version 24H2 (10.0.26100.0 to before 10.0.26100.9974)
• Windows 11 Version 25H2 (10.0.26200.0 to before 10.0.26200.9974)
• Windows 11 Version 26H1 (10.0.28000.0 to before 10.0.28000.3501)
• Windows 11 Version 26H2 (10.0.26300.0 to before 10.0.26300.9974)
• Windows Server 2016 including Server Core (10.0.14393.0 to before 10.0.14393.9688)
• Windows Server 2019 including Server Core (10.0.17763.0 to before 10.0.17763.9487)
• Windows Server 2022 (10.0.20348.0 to before 10.0.20348.5870)

Fixed in

Fixed in the November 2026 security update. Fixed builds according to the CVE record (verify on MSRC):

• Windows 10 1607 and Windows Server 2016: 10.0.14393.9688
• Windows 10 1809 and Windows Server 2019: 10.0.17763.9487
• Windows 10 21H2: 10.0.19044.7846
• Windows 10 22H2: 10.0.19045.7846
• Windows 11 23H2: 10.0.22631.7711
• Windows 11 24H2, 25H2 and 26H2: 10.0.26100.9974, 10.0.26200.9974 and 10.0.26300.9974
• Windows 11 26H1: 10.0.28000.3501
• Windows Server 2022: 10.0.20348.5870

Workaround

Unknown. No NFS-specific mitigation is documented in the sources reviewed.

• If the Client for NFS feature is not needed, remove it from hosts that do not use it.
• Restrict which NFS servers the clients can reach (not a vendor-documented mitigation).

Exploitation

• The CVSS vector includes E:U (exploit code maturity: unproven) and RC:C (report confidence: confirmed).
• One tracker lists the vulnerability as not exploited.
• No public proof of concept and no in-the-wild exploitation were found. Treat the status as unknown, not as confirmed absent.

Our recommendation

• Apply the November 2026 Windows update on all affected systems and confirm the fixed build for each product on MSRC.
• Inventory hosts with the Client for NFS feature enabled and remove it where it is not used.
• Check whether mounted NFS servers are untrusted or reachable from outside the LAN.
• Re-check NVD and MSRC for updates on exploitation.

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

• Microsoft Security Update Guide: CVE-2026-95885 msrc.microsoft.com
• CVE Record CVE-2026-95885 (CVE Program) www.cve.org
• Strix: CVE-2026-95885 www.strix.ai
• Senserva: KB5131096 tracker page senserva.com
• Qualys: Microsoft Patch Tuesday November 2026 review blog.qualys.com
• Vulners: MS:CVE-2026-70585 (related NFS issue) 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, 01:33.