CVE-2026-85799: Microsoft Network Policy Server use-after-free remote code execution

CVE-2026-85799 · Severity: high · CVSS 8.1 · Published 2026-10-13

Network Policy Server (NPS) is a Microsoft authentication and authorization service used in enterprise networks to control access to critical resources. A use-after-free vulnerability in NPS allows an attacker on the network to execute code remotely without authentication, potentially compromising the entire authentication infrastructure and enabling lateral movement through the network.

Technologies: Microsoft Network Policy Server, Microsoft Windows 10 1607, Microsoft Windows 10 1809, Microsoft Windows 10 21h2, Microsoft Windows 10 22h2, Microsoft Windows 11 23h2, Microsoft Windows 11 24h2, Microsoft Windows 11 25h2, Microsoft Windows 11 26h1, Microsoft Windows 11 26h2, Microsoft Windows Server 2012, Microsoft Windows Server 2016, Microsoft Windows Server 2019, Microsoft Windows Server 2022, Microsoft Windows Server 2025. Vendors: Microsoft.

Quick answers

Is CVE-2026-85799 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-85799 being exploited in the wild.
How severe is CVE-2026-85799?
High severity, with a CVSS score of 8.1, published 13 October 2026.
Which products and versions are affected?
Microsoft Network Policy Server.
Is there a fix for CVE-2026-85799?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-85799 attacked?
It is attacked over the network, in a hosted service.
Am I affected by CVE-2026-85799?
Check whether you run Microsoft Network Policy Server, Microsoft Windows 10 1607, Microsoft Windows 10 1809 or one of the others listed. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A use-after-free vulnerability in Microsoft Network Policy Server allows remote code execution over the network without prior authentication. The vulnerability is in memory management within NPS and can be exploited by sending specially crafted network packets to trigger the freed memory access.

Affected products

  • Microsoft Network Policy Server

Timeline

  • 2026-10-13: disclosed

References

This page as Markdown. Free to reuse under CC BY 4.0 with a link back.