Back to vendor advisories
Microsoft Security Response CenterCVE-2026-33096

HTTP.sys Denial of Service Vulnerability

Out-of-bounds read in Windows HTTP.sys allows an unauthorized attacker to deny service over a network.

7.5CVSS out of 10High severity
Scope

What the vendor says is affected

  • 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 (Server Core installation)
  • Windows 11 Version 25H2 for ARM64-based Systems
  • Windows 11 Version 25H2 for x64-based Systems
  • Windows 11 Version 23H2 for ARM64-based Systems
  • Windows 11 Version 23H2 for x64-based Systems
  • Windows Server 2022, 23H2 Edition (Server Core installation)
  • Windows 11 Version 24H2 for ARM64-based Systems
  • Windows 11 Version 24H2 for x64-based Systems
  • Windows Server 2025

Versions the vendor lists as fixed

  • 10.0.28000.1836
  • 10.0.20348.5020
  • 10.0.26100.32690
  • 10.0.26200.8246
  • 10.0.22631.6936
  • 10.0.25398.2274
  • 10.0.26100.8246
Next step

What the vendor recommends

Mitigation refers to a setting, common configuration, or general best-practice, existing in a default state, that could reduce the severity of exploitation of a vulnerability. The following mitigating factors might help in your situation: Caution Follow these steps carefully. Serious problems might occur if you modify the registry incorrectly. To disable HTTP/3, remove the following registry value Install KB5083768. Install KB5082142. Install KB5082063. Install KB5083769. Install KB5082052. Install KB5082060.

Review the complete instructions on the vendor's site
Timeline

When this advisory changed

  1. Published by Microsoft Security Response Center

    The publication date reported by the vendor.

  2. Added to SecurityAlert

    We collected the advisory from the official source.

Vulnerabilities

CVEs named in this advisory