Microsoft Windows up to Server 2025 Remote Desktop Services privileges management

Summaryinfo

A vulnerability was found in Microsoft Windows. It has been rated as critical. This affects an unknown part of the component Remote Desktop Services. Performing a manipulation results in privileges management. This vulnerability was named CVE-2026-21533. The attack needs to be approached locally. In addition, an exploit is available. It is recommended to apply a patch to fix this issue.

Detailsinfo

A vulnerability classified as critical has been found in Microsoft Windows. This affects an unknown function of the component Remote Desktop Services. The manipulation with an unknown input leads to a privileges management vulnerability. CWE is classifying the issue as CWE-269. The product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

Improper privilege management in Windows Remote Desktop allows an authorized attacker to elevate privileges locally.

The weakness was presented 02/10/2026 as confirmed security update guide (Website). It is possible to read the advisory at msrc.microsoft.com. This vulnerability is uniquely identified as CVE-2026-21533. The exploitability is told to be easy. Attacking locally is a requirement. Technical details are unknown but an exploit is available. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 03/27/2026). The attack technique deployed by this issue is T1068 according to MITRE ATT&CK.

It is declared as attacked. The CISA Known Exploited Vulnerabilities Catalog lists this issue since 02/10/2026 with a due date of 03/03/2026:

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

Applying a patch is able to eliminate this problem. A possible mitigation has been published immediately after the disclosure of the vulnerability.

The vulnerability is also documented in the vulnerability database at Zero-Day.cz (1072). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Microsoft

Name

• Windows

Version

• 10 21H2
• 10 22H2
• 10 1607
• 10 1809
• 11 23H2
• 11 24H2
• 11 25H2
• 11 26H1
• Server 2012
• Server 2012 R2
• Server 2016
• Server 2019
• Server 2022
• Server 2022 23H2
• Server 2025

License

• commercial

Website

• Vendor: https://www.microsoft.com/
• Product: https://www.microsoft.com/en-us/windows

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Be aware that VulDB is the high quality source for vulnerability data.

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