Patch tracker / CVE reference / CVE-2026-45657
CVE-2026-45657
CVE-2026-45657 is a Microsoft vulnerability that Microsoft rates Critical, with a CVSS score of 9.8 (Critical). Microsoft has shipped the fix: deploy one of the 5 updates below from the Microsoft Update Catalog, and see where this CVE sits against the rest on the patch tracker.
Risk summary
Not in the CISA KEV catalog. EPSS exploit probability 2.6%. CVSS 9.8 (Critical).
This CVE is among the lower half of tracked Microsoft CVEs by EPSS exploit probability.
This is an unauthenticated kernel-level remote code execution flaw in Windows Server 2022 and Server 2025 Server Core, rated Severity Critical at CVSS 9.8. Kernel RCE means a successful hit runs with full system privileges, and the 54 percent EPSS score signals working exploit code is likely to circulate soon even though CISA KEV has not yet confirmed active exploitation. Server Core and headless server roles are directly in scope, so exposed management or file-serving interfaces are the concern.
Do this: Deploy Microsoft's patch for CVE-2026-45657 to all Windows Server 2022 and 2025 Server Core hosts now, prioritizing internet-facing and domain-critical servers.
AI-generated from public data, 2026-07-26. Verify against the vendor advisory before acting.
Senserva AI Opinion and rich prompt for CVE-2026-45657
Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.
Official patch(es) for CVE-2026-45657
Elevated priority: high severity or a meaningful exploitation probability, sooner if an affected product is internet-facing. In Intune or Defender, confirm whether the fixing updates KB5093998, KB5094125, KB5094126, KB5094128, KB5095051 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-2026-45657. 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 22H2 for ARM64-based Systems
- Windows 11 Version 22H2 for x64-based Systems
- 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 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.