CVE-2026-47291

CRITICAL

Microsoft Windows HTTP.sys - Remote Code Execution via Integer Overflow

Title source: manual
STIX 2.1

Exploitation Summary

EIP tracks 2 public exploits for CVE-2026-47291. PoCs published by dhmosfunk, ManagerEmpty.

AI-analyzed exploit summary The repository contains a functional Python script that exploits CVE-2026-47291, a denial-of-service vulnerability in HTTP.sys. The script sends a large number of HTTP/2 headers to trigger an integer overflow in the HTTP.sys driver, leading to a system crash or instability.

Description

Integer overflow or wraparound in Windows HTTP.sys allows an unauthorized attacker to execute code over a network.

Exploits (2)

github WORKING POC
by dhmosfunk · pythonpoc
https://github.com/dhmosfunk/CVE-2026-49160-CVE-2026-47291-HTTP.sys

The repository contains a functional Python script that exploits CVE-2026-47291, a denial-of-service vulnerability in HTTP.sys. The script sends a large number of HTTP/2 headers to trigger an integer overflow in the HTTP.sys driver, leading to a system crash or instability.

Classification
Working Poc 95%
Attack Type
Dos
Complexity
Moderate
Reliability
Reliable
Target: Microsoft HTTP.sys (Windows HTTP Protocol Stack)
No auth needed
Prerequisites: HTTP/2 enabled server · Network access to the target
devstral-2 · analyzed Jun 16, 2026 Full analysis →
github SUSPICIOUS
by ManagerEmpty · poc
https://github.com/ManagerEmpty/CVE-2026-47291-httpsys

The repository claims to provide an RCE exploit for CVE-2026-47291 targeting Windows HTTP.sys but lacks actual exploit code, instead redirecting to an external download link via a URL shortener. The README contains technical details but no functional code, which is a common tactic for malicious or monetized exploit lures.

Classification
Suspicious 95%
Attack Type
Rce
Complexity
Theoretical
Reliability
Theoretical
Target: Windows HTTP.sys (Windows 10/11, Server 2012-2025)
No auth needed
Prerequisites: Windows system with vulnerable HTTP.sys version
devstral-2 · analyzed Jun 11, 2026 Full analysis →

References (1)

Core 1
Core References
Vendor Advisory vendor-advisory patch
HTTP.sys Remote Code Execution Vulnerability
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-47291

Scores

CVSS v3 9.8
EPSS 0.0430
EPSS Percentile 89.9%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact total

Details

CWE
CWE-122 CWE-190
Status published
Products (33)
Microsoft/Windows 10 Version 1607 10.0.14393.0 - 10.0.14393.9234
Microsoft/Windows 10 Version 1809 10.0.17763.0 - 10.0.17763.8880
Microsoft/Windows 10 Version 21H2 10.0.19044.0 - 10.0.19044.7417
Microsoft/Windows 10 Version 22H2 10.0.19045.0 - 10.0.19045.7417
Microsoft/Windows 11 version 23H2 10.0.22631.0 - 10.0.22631.7219
Microsoft/Windows 11 Version 24H2 10.0.26100.0 - 10.0.26100.8655
Microsoft/Windows 11 Version 25H2 10.0.26200.0 - 10.0.26200.8655
Microsoft/Windows 11 version 26H1 10.0.28000.0 - 10.0.28000.2269
Microsoft/Windows Server 2012 6.2.9200.0 - 6.2.9200.26132
Microsoft/Windows Server 2012 (Server Core installation) 6.2.9200.0 - 6.2.9200.26132
... and 23 more
Published Jun 09, 2026
Tracked Since Jun 09, 2026