Windows 11 21H2 vulnerabilitiesAnd the versions its exploited flaws hit.
Windows 11 21H2 is made by Microsoft. We track 1,031 published vulnerabilities in it, across 73 versions. 66 of them are on the list of flaws known to be exploited, the newest added on 13 April 2026. If you run Windows 11 21H2, check your version against the exploited flaws below and patch those first.
The most recent Windows 11 21H2 flaw added to the known-exploited list is CVE-2023-36424, on 13 April 2026. We keep watching the known-exploited list.
Which versions of Windows 11 21H2 do the exploited flaws hit?
Each exploited flaw lists the versions it affects, usually as ranges. "before 10.0.22000.2600" means every version up to, but not including, 10.0.22000.2600. Find your version, then patch.
- CVE-2023-36424Exploited list, 13 Apr 2026
Microsoft Windows Out-of-Bounds Read Vulnerability
before 10.0.22000.2600 - CVE-2024-35250Exploited list, 16 Dec 2024
Microsoft Windows Kernel-Mode Driver Untrusted Pointer Dereference Vulnerability
before 10.0.22000.3019 - CVE-2024-30088Exploited list, 15 Oct 2024
Microsoft Windows Kernel TOCTOU Race Condition Vulnerability
before 10.0.22000.3019 - CVE-2024-43573Exploited list, 8 Oct 2024
Microsoft Windows MSHTML Platform Spoofing Vulnerability
before 10.0.22000.3260 - CVE-2024-43572Exploited list, 8 Oct 2024
Microsoft Windows Management Console Remote Code Execution Vulnerability
before 10.0.22000.3260 - CVE-2024-43461Exploited list, 16 Sep 2024
Microsoft Windows MSHTML Platform Spoofing Vulnerability
before 10.0.22000.3197 - CVE-2024-38217Exploited list, 10 Sep 2024
Microsoft Windows Mark of the Web (MOTW) Protection Mechanism Failure Vulnerability
before 10.0.22000.3197 - CVE-2024-38014Exploited list, 10 Sep 2024
Microsoft Windows Installer Improper Privilege Management Vulnerability
before 10.0.22000.3197 - CVE-2024-38107Exploited list, 13 Aug 2024
Microsoft Windows Power Dependency Coordinator Privilege Escalation Vulnerability
before 10.0.22000.3147 - CVE-2024-38106Exploited list, 13 Aug 2024
Microsoft Windows Kernel Privilege Escalation Vulnerability
before 10.0.22000.3147 - CVE-2024-38193Exploited list, 13 Aug 2024
Microsoft Windows Ancillary Function Driver for WinSock Privilege Escalation Vulnerability
before 10.0.22000.3147 - CVE-2024-38213Exploited list, 13 Aug 2024
Microsoft Windows SmartScreen Security Feature Bypass Vulnerability
before 10.0.22000.3019 - CVE-2024-38178Exploited list, 13 Aug 2024
Microsoft Windows Scripting Engine Memory Corruption Vulnerability
before 10.0.22000.3147 - CVE-2024-38080Exploited list, 9 Jul 2024
Microsoft Windows Hyper-V Privilege Escalation Vulnerability
before 10.0.22000.3079 - CVE-2024-38112Exploited list, 9 Jul 2024
Microsoft Windows MSHTML Platform Spoofing Vulnerability
before 10.0.22000.3079 - CVE-2024-26169Exploited list, 13 Jun 2024
Microsoft Windows Error Reporting Service Improper Privilege Management Vulnerability
before 10.0.22000.2836 - CVE-2024-30040Exploited list, 14 May 2024
Microsoft Windows MSHTML Platform Security Feature Bypass Vulnerability
before 10.0.22000.2960 - CVE-2024-30051Exploited list, 14 May 2024
Microsoft DWM Core Library Privilege Escalation Vulnerability
before 10.0.22000.2960 - CVE-2024-21338Exploited list, 4 Mar 2024
Microsoft Windows Kernel Exposed IOCTL with Insufficient Access Control Vulnerability
before 10.0.22000.2777 - CVE-2023-29360Exploited list, 29 Feb 2024
Microsoft Streaming Service Untrusted Pointer Dereference Vulnerability
before 10.0.22000.2057 - CVE-2024-21412Exploited list, 13 Feb 2024
Microsoft Windows Internet Shortcut Files Security Feature Bypass Vulnerability
before 10.0.22000.2777 - CVE-2024-21351Exploited list, 13 Feb 2024
Microsoft Windows SmartScreen Security Feature Bypass Vulnerability
before 10.0.22000.2777 - CVE-2023-36584Exploited list, 16 Nov 2023
Microsoft Windows Mark of the Web (MOTW) Security Feature Bypass Vulnerability
before 10.0.22000.2538 - CVE-2023-36033Exploited list, 14 Nov 2023
Microsoft Windows Desktop Window Manager (DWM) Core Library Privilege Escalation Vulnerability
before 10.0.22000.2600 - CVE-2023-36036Exploited list, 14 Nov 2023
Microsoft Windows Cloud Files Mini Filter Driver Privilege Escalation Vulnerability
before 10.0.22000.2600 - CVE-2023-36563Exploited list, 10 Oct 2023
Microsoft WordPad Information Disclosure Vulnerability
before 10.0.22000.2538 - CVE-2023-44487Exploited list, 10 Oct 2023
HTTP/2 Rapid Reset Attack Vulnerability
before 10.0.22000.2538 - CVE-2023-28229Exploited list, 4 Oct 2023
Microsoft Windows CNG Key Isolation Service Privilege Escalation Vulnerability
before 10.0.22000.1817
2 more exploited flaws name Windows 11 21H2 without a version of its own, for example as the system other affected software runs on. They are in the list below.
Showing the 30 most recently added of 66 exploited flaws. The full list is below.
Which Windows 11 21H2 vulnerabilities are being exploited?
50 flaws are on the government list of vulnerabilities known to be exploited. These are the ones criminals are using now, so they go first, whatever their severity score says.
- 7.8Microsoft Windows Out-of-Bounds Read Vulnerability
Microsoft Windows Common Log File System Driver contains an out-of-bounds read vulnerability that could allow a threat actor for privileges escalation
- 7.5Microsoft .NET Framework Information Disclosure Vulnerability
Microsoft .NET Framework contains an information disclosure vulnerability that exposes the ObjRef URI to an attacker, ultimately enabling remote code execution.
- 7.8Microsoft Windows Kernel-Mode Driver Untrusted Pointer Dereference Vulnerability
Microsoft Windows Kernel-Mode Driver contains an untrusted pointer dereference vulnerability that allows a local attacker to escalate privileges.
- 7.0Microsoft Windows Kernel TOCTOU Race Condition Vulnerability
Microsoft Windows Kernel contains a time-of-check to time-of-use (TOCTOU) race condition vulnerability that could allow for privilege escalation.
- 8.1Microsoft Windows MSHTML Platform Spoofing Vulnerability
Microsoft Windows MSHTML Platform contains an unspecified spoofing vulnerability which can lead to a loss of confidentiality.
- 7.8Microsoft Windows Management Console Remote Code Execution Vulnerability
Microsoft Windows Management Console contains unspecified vulnerability that allows for remote code execution.
- 8.8Microsoft Windows MSHTML Platform Spoofing Vulnerability
Microsoft Windows MSHTML Platform contains a user interface (UI) misrepresentation of critical information vulnerability that allows an attacker to spoof a web page.
- 5.4Microsoft Windows Mark of the Web (MOTW) Protection Mechanism Failure Vulnerability
Microsoft Windows Mark of the Web (MOTW) contains a protection mechanism failure vulnerability that allows an attacker to bypass MOTW-based defenses.
Which Windows 11 21H2 flaws are most likely to be used?
Ranked by the latest exploit-likelihood forecast: the chance each flaw is used in an attack in the next 30 days. A high severity score on its own doesn't tell you that. Flaws shared by many other makers' products are left out.
- >99%
The HTTP/2 protocol allows a denial of service (server resource consumption) because request cancellation can reset many streams quickly, as exploited in the wild in August through October 2023.
- >99%
<p>A remote code execution vulnerability exists when the Windows Print Spooler service improperly performs privileged file operations.
- >99%
Internet Shortcut Files Security Feature Bypass Vulnerability
- >99%
A remote code execution vulnerability exists when MSDT is called using the URL protocol from a calling application such as Word.
- 99%
Windows Search Remote Code Execution Vulnerability
- 99%
.NET Framework Information Disclosure Vulnerability
- 95%CVE-2023-21554Critical
Microsoft Message Queuing (MSMQ) Remote Code Execution Vulnerability
- 93%CVE-2023-35628High
Windows MSHTML Platform Remote Code Execution Vulnerability
- 93%CVE-2023-28302High
Microsoft Message Queuing (MSMQ) Denial of Service Vulnerability
- 89%CVE-2023-21547High
Internet Key Exchange (IKE) Protocol Denial of Service Vulnerability
Running Windows 11 21H2? We'll keep checking.
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1 flaw being exploited affects software Acme tracks
Microsoft Windows Common Log File System Driver contains an out-of-bounds read vulnerability that could allow a threat actor for privileges escalation
- Matched to
- Windows 11 21H2 on Acme's software list
- What to do
- Patch first, then check for signs of use
Sent to the alert recipients Acme chose. Also in the app and to Acme's webhook.
We track 1,031 published vulnerabilities listed under the name Windows 11 21H2, across 73 versions. The most recent Windows 11 21H2 flaw added to the known-exploited list is CVE-2023-36424, on 13 April 2026.
66 are on the list of flaws known to be exploited. The most recently added are CVE-2023-36424, CVE-2024-29059 and CVE-2024-35250.
Each flaw names its own versions, usually as ranges. The newest, CVE-2023-36424, affects before 10.0.22000.2600. The versions for every exploited flaw are listed on this page.
Create a Precursor Intelligence account and track Windows 11 21H2. We match it against every published flaw, give each one a risk score from 0 to 100 and keep watching, so you hear about new ones as soon as we know, by email, in the app or by webhook.