Windows
CVE-2026-21231
HIGH
Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain
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AccessGain local system access
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ExploitIdentify vulnerable kernel shared resource
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ExecutionTrigger race condition through concurrent operations
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ImpactAchieve privilege escalation to system level
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A06:2025 - Insecure Design
ASVS 5.0
V15 - Secure Coding and Architecture Concurrency control, locking
MITRE ATT&CK
1 technique across 1 tactic: Privilege Escalation The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Exploitation Conditions | Requires local authenticated user account on Windows system. Attacker must exploit a specific kernel synchronization vulnerability (CWE-362) accessible only to users with existing login privileges. High attack complexity due to race condition timing requirements. |
| Impact | CVSS 7.8 (HIGH). Attack vector: Local. Complexity: High. Privileges required: Low. User interaction: None. Exploitable via local access. |
| Exploit ScenarioDerived | An attacker could exploit this vulnerability to compromise the affected system. |
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Alert meAnalysisAIv1 – Mar 12, 2026
Windows Kernel privilege escalation vulnerability in Windows 10 21H2 and Windows Server 2012 stems from improper synchronization of concurrent access to shared resources, enabling local authenticated users to gain elevated system privileges. The race condition can be triggered without user interaction and impacts confidentiality, integrity, and availability of the affected system. No patch is currently available.
Earlier versions of this analysis (1)
Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Kernel allows an authorized attacker to elevate privileges locally. [CVSS 7.8 HIGH]
RemediationAI
Monitor vendor advisories for a patch.
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 15 packages in microsoft
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
Classified as CWE-362 (Race Condition). Affects Windows 10 1607. Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Kernel allows an authorized attacker to elevate privileges locally.
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- Exploit and PoC references, threat intelligence from 22 sources
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Severity by source
AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
DescriptionCVE.org
Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Kernel allows an authorized attacker to elevate privileges locally.
Executive ViewAI
A privilege escalation vulnerability in the Windows Kernel (CVE-2026-21231) allows authenticated users to gain elevated system access, potentially compromising sensitive data and critical systems. This poses significant risk to organizations running Windows infrastructure, particularly those with privileged user accounts or contractor access.
Restrict local administrator account usage and enforce non-admin user policies; disable unused local logon capabilities; implement privileged access management (PAM) solutions to control and audit elevated access; segment internal networks to limit lateral movement post-exploitation; enable enhanced logging and monitoring of privilege escalation attempts; apply principle of least privilege across all user accounts; consider temporary restriction of local logon access for non-essential user classes until patch availability.
Threat Intelligence Overview
NVD
CVE.org
EPSS
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Race conditions occur when multiple concurrent requests exploit the brief time gap between checking a condition and acting upon it (TOCTOU - Time of Check, Time of Use).
Affected Products (CPE)CVE.org
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Windows Internet Shortcut Files (.url) contain an external control vulnerability (CVE-2025-33053, CVSS 8.8) that enables
Windows SMB contains an improper access control vulnerability (CVE-2025-33073, CVSS 8.8) enabling authenticated attacker
An unrestricted file upload vulnerability exists in MiniWeb HTTP Server <= Build 300 that allows unauthenticated remote
FreeFloat FTP Server contains multiple critical design flaws that allow unauthenticated remote attackers to upload arbit
Serviio Media Server versions 1.4 through 1.8 on Windows contain an unauthenticated command injection in the /rest/actio
Mako Server versions 2.5 and 2.6 contain an unauthenticated OS command injection via the tutorial interface at examples/
React Native Metro Development Server binds to external interfaces by default and contains an OS command injection endpo
Command injection in the Windows Shell lets remote, unauthenticated attackers bypass a Windows security feature and then
External control of file name or path in Windows NTLM allows an unauthorized attacker to perform spoofing over a network
GitHub PoC
Exploit-DB