Patch tracker / CVE reference / CVE-2026-33827
CVE-2026-33827
CVE-2026-33827 is a high severity Microsoft vulnerability with a CVSS score of 8.1. Its EPSS score puts the probability of exploitation in the next 30 days at 73%. Microsoft has shipped the fix: deploy one of the 11 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 73%. CVSS 8.1 (High).
This CVE is among the top 25% of tracked Microsoft CVEs by EPSS exploit probability.
Another Critical CVSS 9.8 hole in the Windows TCP/IP stack on Windows 10 1809 and Server 2019, this one with a 64 percent EPSS score. Like its sibling CVE-2026-40415, it sits below every application and firewall rule that only filters by port, so exposure is defined by network reachability alone. Two stack bugs at once raises the chance that public exploit tooling covers both.
Do this: Bundle this with the CVE-2026-40415 patching effort and verify perimeter and segmentation rules limit which 1809 and Server 2019 hosts accept traffic from untrusted networks.
AI-generated from public data, 2026-07-07. Verify against the vendor advisory before acting.
Senserva AI Opinion and rich prompt for CVE-2026-33827
Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.
Official patch(es) for CVE-2026-33827
High priority: EPSS puts the odds of near-term exploitation high. In Intune or Defender, confirm whether the fixing updates KB5082052, KB5082060, KB5082063, KB5082123, KB5082126, KB5082127, KB5082142, KB5082198, KB5082200, KB5083768, KB5083769 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-2026-33827. 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 10 Version 1809 for 32-bit Systems
- Windows 10 Version 1809 for x64-based Systems
- Windows 11 Version 24H2 for x64-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 2019
- 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.