Windows 10 21H2 vulnerabilitiesAnd the versions its exploited flaws hit.
Windows 10 21H2 is made by Microsoft. We track 1,430 published vulnerabilities in it, across 86 versions. 87 of them are on the list of flaws known to be exploited, the newest added on 8 September 2026. If you run Windows 10 21H2, check your version against the exploited flaws below and patch those first.
The most recent Windows 10 21H2 flaw added to the known-exploited list is CVE-2026-85880, on 8 September 2026. We keep watching the known-exploited list.
Which versions of Windows 10 21H2 do the exploited flaws hit?
Each exploited flaw lists the versions it affects, usually as ranges. "before 10.0.19044.7725" means every version up to, but not including, 10.0.19044.7725. Find your version, then patch.
- CVE-2026-85880Exploited list, 8 Sep 2026
Microsoft Windows Heap-Based Buffer Overflow Vulnerability
before 10.0.19044.7725 - CVE-2023-36424Exploited list, 13 Apr 2026
Microsoft Windows Out-of-Bounds Read Vulnerability
before 10.0.19041.3693 - CVE-2025-33073Exploited list, 20 Oct 2025
Microsoft Windows SMB Client Improper Access Control Vulnerability
before 10.0.19044.5965 - CVE-2025-24990Exploited list, 14 Oct 2025
Microsoft Windows Untrusted Pointer Dereference Vulnerability
before 10.0.19044.6456 - CVE-2025-59230Exploited list, 14 Oct 2025
Microsoft Windows Improper Access Control Vulnerability
before 10.0.19044.6456 - CVE-2025-47827Exploited list, 14 Oct 2025
IGEL OS Use of a Key Past its Expiration Date Vulnerability
before 10.0.19044.6456 - CVE-2025-33053Exploited list, 10 Jun 2025
Microsoft Windows External Control of File Name or Path Vulnerability
before 10.0.19044.5965 - CVE-2025-32709Exploited list, 13 May 2025
Microsoft Windows Ancillary Function Driver for WinSock Use-After-Free Vulnerability
before 10.0.19044.5854 - CVE-2025-32706Exploited list, 13 May 2025
Microsoft Windows Common Log File System (CLFS) Driver Heap-Based Buffer Overflow Vulnerability
before 10.0.19044.5854 - CVE-2025-32701Exploited list, 13 May 2025
Microsoft Windows Common Log File System (CLFS) Driver Use-After-Free Vulnerability
before 10.0.19044.5854 - CVE-2025-30400Exploited list, 13 May 2025
Microsoft Windows DWM Core Library Use-After-Free Vulnerability
before 10.0.19044.5854 - CVE-2025-30397Exploited list, 13 May 2025
Microsoft Windows Scripting Engine Type Confusion Vulnerability
before 10.0.19044.5854 - CVE-2025-24054Exploited list, 17 Apr 2025
Microsoft Windows NTLM Hash Disclosure Spoofing Vulnerability
before 10.0.19044.5608 - CVE-2025-29824Exploited list, 8 Apr 2025
Microsoft Windows Common Log File System (CLFS) Driver Use-After-Free Vulnerability
before 10.0.19044.5737 - CVE-2025-24993Exploited list, 11 Mar 2025
Microsoft Windows NTFS Heap-Based Buffer Overflow Vulnerability
before 10.0.19044.5608 - CVE-2025-24991Exploited list, 11 Mar 2025
Microsoft Windows NTFS Out-Of-Bounds Read Vulnerability
before 10.0.19044.5608 - CVE-2025-26633Exploited list, 11 Mar 2025
Microsoft Windows Management Console (MMC) Improper Neutralization Vulnerability
before 10.0.19044.5608 - CVE-2025-24985Exploited list, 11 Mar 2025
Microsoft Windows Fast FAT File System Driver Integer Overflow Vulnerability
before 10.0.19044.5608 - CVE-2025-24984Exploited list, 11 Mar 2025
Microsoft Windows NTFS Information Disclosure Vulnerability
before 10.0.19044.5608 - CVE-2025-21391Exploited list, 11 Feb 2025
Microsoft Windows Storage Link Following Vulnerability
before 10.0.19044.5487 - CVE-2025-21418Exploited list, 11 Feb 2025
Microsoft Windows Ancillary Function Driver for WinSock Heap-Based Buffer Overflow Vulnerability
before 10.0.19044.5487 - CVE-2025-21333Exploited list, 14 Jan 2025
Microsoft Windows Hyper-V NT Kernel Integration VSP Heap-based Buffer Overflow Vulnerability
before 10.0.19044.5371 - CVE-2025-21335Exploited list, 14 Jan 2025
Microsoft Windows Hyper-V NT Kernel Integration VSP Use-After-Free Vulnerability
before 10.0.19044.5371 - CVE-2025-21334Exploited list, 14 Jan 2025
Microsoft Windows Hyper-V NT Kernel Integration VSP Use-After-Free Vulnerability
before 10.0.19044.5371 - CVE-2024-35250Exploited list, 16 Dec 2024
Microsoft Windows Kernel-Mode Driver Untrusted Pointer Dereference Vulnerability
before 10.0.19044.4529 - CVE-2024-49138Exploited list, 10 Dec 2024
Microsoft Windows Common Log File System (CLFS) Driver Heap-Based Buffer Overflow Vulnerability
before 10.0.19044.5247 - CVE-2024-43451Exploited list, 12 Nov 2024
Microsoft Windows NTLMv2 Hash Disclosure Spoofing Vulnerability
before 10.0.19044.5131 - CVE-2024-49039Exploited list, 12 Nov 2024
Microsoft Windows Task Scheduler Privilege Escalation Vulnerability
before 10.0.19044.5131 - CVE-2024-30088Exploited list, 15 Oct 2024
Microsoft Windows Kernel TOCTOU Race Condition Vulnerability
before 10.0.19044.4529
1 more exploited flaw names Windows 10 21H2 without a version of its own, for example as the system other affected software runs on. It is in the list below.
Showing the 30 most recently added of 87 exploited flaws. The full list is below.
Which Windows 10 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 Heap-Based Buffer Overflow Vulnerability
Microsoft Windows Advanced Local Procedure Call contains a heap-based buffer overflow vulnerability that allows an attacker to elevate privileges locally.
- 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
- 8.8Microsoft Windows SMB Client Improper Access Control Vulnerability
Microsoft Windows SMB Client contains an improper access control vulnerability that could allow for privilege escalation.
- 7.8Microsoft Windows Untrusted Pointer Dereference Vulnerability
Microsoft Windows Agere Modem Driver contains an untrusted pointer dereference vulnerability that allows for privilege escalation.
- 7.8Microsoft Windows Improper Access Control Vulnerability
Microsoft Windows contains an improper access control vulnerability in Windows Remote Access Connection Manager which could allow an authorized attacker to elevate privileges locally.
- 4.6IGEL OS Use of a Key Past its Expiration Date Vulnerability
IGEL OS contains a use of a key past its expiration date vulnerability that allows for Secure Boot bypass.
- 8.8Microsoft Windows External Control of File Name or Path Vulnerability
Microsoft Windows contains an external control of file name or path vulnerability that could allow an attacker to execute code from a remote WebDAV location specified by the WorkingDirectory attribute of Internet...
- 7.8Microsoft Windows Ancillary Function Driver for WinSock Use-After-Free Vulnerability
Microsoft Windows Ancillary Function Driver for WinSock contains a use-after-free vulnerability that allows an authorized attacker to escalate privileges to administrator.
Which Windows 10 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 10 21H2? We'll keep checking.
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1 flaw being exploited affects software Acme tracks
Microsoft Windows Advanced Local Procedure Call contains a heap-based buffer overflow vulnerability that allows an attacker to elevate privileges locally.
- Matched to
- Windows 10 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 1,430 published vulnerabilities listed under the name Windows 10 21H2, across 86 versions. The most recent Windows 10 21H2 flaw added to the known-exploited list is CVE-2026-85880, on 8 September 2026.
87 are on the list of flaws known to be exploited. The most recently added are CVE-2026-85880, CVE-2023-36424 and CVE-2025-33073.
Each flaw names its own versions, usually as ranges. The newest, CVE-2026-85880, affects before 10.0.19044.7725. The versions for every exploited flaw are listed on this page.
Create a Precursor Intelligence account and track Windows 10 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.