---
id: CVE-2026-47291
title: HTTP.sys Remote Code Execution Vulnerability
summary: >-
  Integer overflow or wraparound in Windows HTTP.sys allows an unauthorized
  attacker to execute code over a network.
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C'
cvssSource: cna
cwe:
  - CWE-190
  - CWE-122
vendor: Microsoft
product: Windows 10 Version 1607
affected:
  - windows_10_version_1607 >= 10.0.14393.0 < 10.0.14393.9234
  - windows_10_version_1809 >= 10.0.17763.0 < 10.0.17763.8880
  - windows_10_version_21h2 >= 10.0.19044.0 < 10.0.19044.7417
  - windows_10_version_22h2 >= 10.0.19045.0 < 10.0.19045.7417
  - windows_11_version_23h2 >= 10.0.22631.0 < 10.0.22631.7219
  - windows_11_version_23h2 >= 10.0.22631.0 < 10.0.22631.7219
  - windows_11_version_24h2 >= 10.0.26100.0 < 10.0.26100.8655
  - windows_11_version_25h2 >= 10.0.26200.0 < 10.0.26200.8655
  - windows_11_version_26h1 >= 10.0.28000.0 < 10.0.28000.2269
  - windows_server_2012 >= 6.2.9200.0 < 6.2.9200.26132
  - windows_server_2012_server_core_installation >= 6.2.9200.0 < 6.2.9200.26132
  - windows_server_2012_r2 >= 6.3.9600.0 < 6.3.9600.23228
  - >-
    windows_server_2012_r2_server_core_installation >= 6.3.9600.0 <
    6.3.9600.23228
  - windows_server_2016 >= 10.0.14393.0 < 10.0.14393.9234
  - >-
    windows_server_2016_server_core_installation >= 10.0.14393.0 <
    10.0.14393.9234
  - windows_server_2019 >= 10.0.17763.0 < 10.0.17763.8880
  - >-
    windows_server_2019_server_core_installation >= 10.0.17763.0 <
    10.0.17763.8880
  - windows_server_2022 >= 10.0.20348.0 < 10.0.20348.5256
  - windows_server_2025 >= 10.0.26100.0 < 10.0.26100.32995
  - >-
    windows_server_2025_server_core_installation >= 10.0.26100.0 <
    10.0.26100.32995
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: total
  timestamp: '2026-06-10T03:57:43.508569Z'
published: '2026-06-09'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T13:43:59.762Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-47291'
references:
  - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-47291'
    label: HTTP.sys Remote Code Execution Vulnerability
tags:
  - cve.org
epss: 0.2275
epssPercentile: 0.97628
ingestedAt: '2026-09-24T14:44:21.417Z'
---

## Overview

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

## Affected

- `windows_10_version_1607 >= 10.0.14393.0 < 10.0.14393.9234`
- `windows_10_version_1809 >= 10.0.17763.0 < 10.0.17763.8880`
- `windows_10_version_21h2 >= 10.0.19044.0 < 10.0.19044.7417`
- `windows_10_version_22h2 >= 10.0.19045.0 < 10.0.19045.7417`
- `windows_11_version_23h2 >= 10.0.22631.0 < 10.0.22631.7219`
- `windows_11_version_23h2 >= 10.0.22631.0 < 10.0.22631.7219`
- `windows_11_version_24h2 >= 10.0.26100.0 < 10.0.26100.8655`
- `windows_11_version_25h2 >= 10.0.26200.0 < 10.0.26200.8655`
- `windows_11_version_26h1 >= 10.0.28000.0 < 10.0.28000.2269`
- `windows_server_2012 >= 6.2.9200.0 < 6.2.9200.26132`
- `windows_server_2012_server_core_installation >= 6.2.9200.0 < 6.2.9200.26132`
- `windows_server_2012_r2 >= 6.3.9600.0 < 6.3.9600.23228`
- `windows_server_2012_r2_server_core_installation >= 6.3.9600.0 < 6.3.9600.23228`
- `windows_server_2016 >= 10.0.14393.0 < 10.0.14393.9234`
- `windows_server_2016_server_core_installation >= 10.0.14393.0 < 10.0.14393.9234`
- `windows_server_2019 >= 10.0.17763.0 < 10.0.17763.8880`
- `windows_server_2019_server_core_installation >= 10.0.17763.0 < 10.0.17763.8880`
- `windows_server_2022 >= 10.0.20348.0 < 10.0.20348.5256`
- `windows_server_2025 >= 10.0.26100.0 < 10.0.26100.32995`
- `windows_server_2025_server_core_installation >= 10.0.26100.0 < 10.0.26100.32995`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.