CVE-2026-21525mediumunder attackCWE-476

CVE-2026-21525: medium-severity vulnerability in Microsoft Windows 10 Version 1607

Windows Remote Access Connection Manager Denial of Service Vulnerability

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43Vexday Risk Score

Prioritize patching. It under exploitation confirmed by CISA and has an official Brazilian government alert.

ssvc Attendcvss 6.2epss 5.0%
from disclosure to weapon
Published on NVDFeb 10
CISA KEVFeb 10
Official alert in Brazil

Brazil's federal government published an alert, recommendation or bulletin that cites this vulnerability.

Source: CTIR Gov (GSI) and CISC Gov.br, under the CC BY-ND 3.0 license.
Action required by CISAfederal deadline: 2026-03-03

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

In short

A flaw in Windows Remote Access Connection Manager causes the program to crash when it tries to use data that doesn't exist. An attacker on the same computer can trigger this crash to interrupt the service.

Technical detail

A null pointer dereference (CWE-476) in the Windows Remote Access Connection Manager allows a local, unauthenticated attacker to cause a denial of service by supplying crafted input that forces the application to access invalid memory references.

Summary generated and translated by AI from the official description.

The full analysis of this CVE is available in Portuguese →

Null pointer dereference in Windows Remote Access Connection Manager allows an unauthorized attacker to deny service locally.
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C
Affected products
Microsoft · Windows 10 Version 1607Microsoft · Windows 10 Version 1809Microsoft · Windows 10 Version 21H2Microsoft · Windows 10 Version 22H2Microsoft · Windows 11 version 22H3Microsoft · Windows 11 Version 23H2Microsoft · Windows 11 Version 24H2Microsoft · Windows 11 Version 25H2Microsoft · Windows 11 version 26H1Microsoft · Windows Server 2012Microsoft · Windows Server 2012 R2Microsoft · Windows Server 2012 R2 (Server Core installation)Microsoft · Windows Server 2012 (Server Core installation)Microsoft · Windows Server 2016Microsoft · Windows Server 2016 (Server Core installation)Microsoft · Windows Server 2019Microsoft · Windows Server 2019 (Server Core installation)Microsoft · Windows Server 2022Microsoft · Windows Server 2022, 23H2 Edition (Server Core installation)Microsoft · Windows Server 2025Microsoft · Windows Server 2025 (Server Core installation)
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