Executive brief
A security vulnerability exists in the Microsoft NAT Helper Components, which are used by Windows to manage network address translation for shared internet connections. An attacker who already has basic access to a computer could exploit this flaw to gain full administrative control over the system. This could lead to unauthorized access to sensitive data, the installation of malicious software, or a complete disruption of business operations on the affected machine.
Technical details
A use-after-free vulnerability (CWE-416) exists in the Microsoft NAT Helper Components, specifically within the ipnathlp.dll library. The flaw is triggered when the system improperly handles objects in memory, allowing an attacker to reuse a memory pointer after it has been freed. To exploit this, an attacker must have local access to the target system with low-level user privileges. Successful exploitation allows the attacker to execute arbitrary code with elevated system privileges. Microsoft has released security updates to address this issue across affected versions of Windows 11 and Windows Server 2025.
Affected products
- Microsoft Windows 11 Version 24H2 10.0.26100.0 to 10.0.26100.8875
- Microsoft Windows 11 Version 25H2 10.0.26200.0 to 10.0.26100.8875
- Microsoft Windows 11 version 26H1 10.0.28000.0 to 10.0.28000.2525
- Microsoft Windows Server 2025 10.0.26100.0 to 10.0.26100.33158
Timeline
- 2026-07-14: disclosed
- 2026-07-14: advisory