Patch tracker / CVE reference / CVE-2026-21241
CVE-2026-21241
CVE-2026-21241 is a Microsoft vulnerability that Microsoft rates Important, with a CVSS score of 7.0 (High). Microsoft has shipped the fix: deploy one of the 9 updates below from the Microsoft Update Catalog, and see where this CVE sits against the rest on the patch tracker.
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Microsoft rates it Important. CVSS 7.0 (High). Fixed by 9 Microsoft security updates.
Risk summary
Not in the CISA KEV catalog. EPSS exploit probability 2.6%. CVSS 7.0 (High).
This CVE is among the top 5% of tracked Microsoft CVEs by EPSS exploit probability.
This WinSock Ancillary Function Driver variant sits at the 26 percent EPSS tier rather than the 4 percent or 64 percent levels seen in the other AFD CVEs in this release, and it affects Windows 11 26H1 and Windows Server 2022 specifically rather than the Windows 10 1809 branch. The mid-range exploit probability still puts it ahead of most other High-severity bugs in urgency. Not confirmed exploited or ransomware-linked.
Do this: Patch Server 2022 and Windows 11 26H1 hosts for this AFD variant even though it is one of several separate WinSock fixes this cycle.
AI-generated from public data, 2026-07-07. Verify against the vendor advisory before acting.
Senserva AI Opinion and rich prompt for CVE-2026-21241
Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.
Official patch(es) for CVE-2026-21241
Moderate priority: schedule it in your normal patch cycle. In Intune or Defender, confirm whether the fixing updates KB5075897, KB5075899, KB5075906, KB5075941, KB5075942, KB5075943, KB5077179, KB5077181, KB5077212 are installed across the affected products. Senserva does this automatically across your tenant and flags every missing patch.
Apply the Microsoft security updates below to fix CVE-2026-21241. Each KB page carries the Microsoft Update Catalog download, Microsoft's known issues for the update, a copy-paste PowerShell check for whether it is installed, and the Senserva AI read.
Scope and sources
- Affected products
- Windows 11 Version 23H2 for ARM64-based Systems
- Windows 11 Version 23H2 for x64-based Systems
- Windows 11 Version 24H2 for ARM64-based Systems
- Windows 11 Version 24H2 for x64-based Systems
- Windows 11 Version 25H2 for ARM64-based Systems
- Windows 11 Version 25H2 for x64-based Systems
- Windows 11 Version 26H1 for ARM64-based Systems
- Windows 11 version 26H1 for x64-based Systems
- Windows Server 2022
- Windows Server 2022 (Server Core installation)
- Windows Server 2022, 23H2 Edition (Server Core installation)
- Windows Server 2025
- Windows Server 2025 (Server Core installation)
- Fixed by the same updates
- Authoritative references
Want every Microsoft CVE and the patches that fix it, ranked by real-world risk? See the Microsoft Patch Tracker.