Known Exploited Vulnerability
7.8
HIGH CVSS 3.1
CVE-2026-21533
Microsoft Windows Improper Privilege Management Vulnerability - [Actively Exploited]
Description

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

INFO

Published Date :

Feb. 10, 2026, 6:16 p.m.

Last Modified :

Feb. 10, 2026, 9:51 p.m.

Remotely Exploit :

No
CISA Notification
CISA KEV (Known Exploited Vulnerabilities)

For the benefit of the cybersecurity community and network defenders—and to help every organization better manage vulnerabilities and keep pace with threat activity—CISA maintains the authoritative source of vulnerabilities that have been exploited in the wild.

Description :

Microsoft Windows Remote Desktop Services contains an improper privilege management vulnerability that could allow an authorized attacker to elevate privileges locally.

Required Action :

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

Notes :

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21533 ; https://nvd.nist.gov/vuln/detail/CVE-2026-21533

Affected Products

The following products are affected by CVE-2026-21533 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 HIGH [email protected]
Solution
Address privilege management flaws to prevent local privilege escalation.
  • Apply updates for Windows Remote Desktop.
  • Review and enforce least privilege principles.
  • Limit local administrator access.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-21533.

URL Resource
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21533
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-21533
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-21533 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-21533 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-21533 vulnerability anywhere in the article.

  • CybersecurityNews
Windows Remote Desktop Services 0-Day Vulnerability Exploited in the Wild to Escalate Privileges

Windows Remote Desktop Services 0-Day Vulnerability Microsoft has patched CVE-2026-21533, a zero-day elevation of privilege vulnerability in Windows Remote Desktop Services (RDS) that attackers are ex ... Read more

Published Date: Feb 11, 2026 (1 hour, 16 minutes ago)
  • TheCyberThrone
Microsoft Patch Tuesday February 2026

Microsoft’s February 2026 Patch Tuesday, released on February 9, 2026, addressed 58 vulnerabilities across Windows, Office, and other components, including six actively exploited zero-days.This update ... Read more

Published Date: Feb 11, 2026 (2 hours, 47 minutes ago)
  • The Register
Microsoft's Valentine's gift to admins: 6 exploited zero-day fixes

What better way to say I love you than with an update? Attackers exploited a whopping six Microsoft bugs as zero-days prior to Redmond releasing software fixes on February's Patch Tuesday. For compari ... Read more

Published Date: Feb 10, 2026 (5 hours, 44 minutes ago)
  • Zero Day Initiative
The February 2026 Security Update Review

I have survived the biggest Pwn2Own ever, but I’m back in Tokyo for the second Patch Tuesday of 2026. My location never stops Patch Tuesday from coming, so let’s take a look at the latest security pat ... Read more

Published Date: Feb 10, 2026 (9 hours, 24 minutes ago)
  • CybersecurityNews
Microsoft Patch Tuesday February 2026 – 54 Vulnerabilities Fixed, Including 6 Zero-days

Microsoft Patch Tuesday February 2026 Microsoft released its February 2026 Patch Tuesday updates on February 10, addressing 54 vulnerabilities, including six zero-days across Windows, Office, Azure, a ... Read more

Published Date: Feb 10, 2026 (9 hours, 43 minutes ago)

The following table lists the changes that have been made to the CVE-2026-21533 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Feb. 10, 2026

    Action Type Old Value New Value
    Added Reference https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-21533
  • New CVE Received by [email protected]

    Feb. 10, 2026

    Action Type Old Value New Value
    Added Description Improper privilege management in Windows Remote Desktop allows an authorized attacker to elevate privileges locally.
    Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
    Added CWE CWE-269
    Added Reference https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21533
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
Vulnerability Scoring Details
Base CVSS Score: 7.8
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact