---
id: CVE-2026-55144
title: 'Windows Cryptography API: Next Generation (CNG) Tampering Vulnerability'
summary: >-
  Missing cryptographic step in Windows CryptoAPI allows an authorized attacker
  to perform tampering locally.
severity: high
cvss: 7.1
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N/E:U/RL:O/RC:C'
cvssSource: cna
cwe:
  - CWE-325
vendor: Microsoft
product: Windows 11 Version 24H2
affected:
  - windows_11_version_24h2 >= 10.0.26100.0 < 10.0.26100.8875
  - windows_11_version_25h2 >= 10.0.26200.0 < 10.0.26200.8875
  - windows_11_version_26h1 >= 10.0.28000.0 < 10.0.28000.2525
  - windows_server_2022 >= 10.0.20348.0 < 10.0.20348.5386
  - windows_server_2025 >= 10.0.26100.0 < 10.0.26100.33158
  - >-
    windows_server_2025_server_core_installation >= 10.0.26100.0 <
    10.0.26100.33158
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-07-20T00:00:00+00:00'
published: '2026-07-14'
updated: '2026-09-25'
sourceUpdated: '2026-09-25T18:20:24.892Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-55144'
references:
  - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55144'
    label: 'Windows Cryptography API: Next Generation (CNG) Tampering Vulnerability'
tags:
  - cve.org
epss: 0.00225
epssPercentile: 0.11851
ingestedAt: '2026-09-08T17:06:31.929Z'
---

## Overview

Missing cryptographic step in Windows CryptoAPI allows an authorized attacker to perform tampering locally.

## Affected

- `windows_11_version_24h2 >= 10.0.26100.0 < 10.0.26100.8875`
- `windows_11_version_25h2 >= 10.0.26200.0 < 10.0.26200.8875`
- `windows_11_version_26h1 >= 10.0.28000.0 < 10.0.28000.2525`
- `windows_server_2022 >= 10.0.20348.0 < 10.0.20348.5386`
- `windows_server_2025 >= 10.0.26100.0 < 10.0.26100.33158`
- `windows_server_2025_server_core_installation >= 10.0.26100.0 < 10.0.26100.33158`

## Remediation

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