CVE-2026-33096: HTTP.sys Denial of Service Vulnerability

Overview

Severity

High (CVSS 7.5)

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C

Category

Denial of Service

Exploit Status

Not Exploited

Exploitation Likelihood

Less Likely

Patch Tuesday

2026-Apr

Released

2026-04-14

Description

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

Affected Products (13)

Windows

• 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 ARM 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

Security Updates (6)

• 5083768
• 5082142
• 5082063
• 5083769
• 5082052
• 5082060

Acknowledgments

WARP & MORSE teams at Microsoft, Milad Nasr (Anthropic) and Calif.io with Claude, WARP & MORSE teams at Microsoft, Milad Nasr (Anthropic) and Calif.io with Claude

Revision History

• 2026-04-14: Information published.