CVE-2026-55144Important
Windows Cryptography API: Next Generation (CNG) Tampering Vulnerability
Assessment
Missing cryptographic step in Windows CryptoAPI allows an authorized attacker to perform tampering locally.
- Severity
- Important
- CVSS base score
- 7.1CVSS:3.1/
AV:L/ AC:L/ PR:L/ UI:N/ S:U/ C:H/ I:H/ A:N/ E:U/ RL:O/ RC:C - Impact
- Tampering
- EPSS, next 30 days
- 0.2%Higher than 11.9% of scored CVEs · FIRST model run 26 Sep 2026 · about EPSS
- Exploitability
- Exploitation Unlikely
- Publicly disclosed
- No
- Customer action
- Required: apply the update
- Component
- Windows CryptoAPI
- Weakness
- CWE-325: Missing Cryptographic Step
- Issued by
- Microsoft
- Published
- 14 Jul 2026 · July 2026
- Last revised
- 14 Jul 2026
Updates that fix it
4 KBs| KB | Type | Restart | Applies to | Other CVEs |
|---|---|---|---|---|
| KB5099536 | Security Update | Required | Windows Server 2025, Windows Server 2025 (Server Core installation) | All CVEs in KB5099536 |
| KB5099540 | Security Update | Required | Windows Server 2022 | All CVEs in KB5099540 |
| KB5101649 | Security Update | Required | Windows 11 Version 26H1 for ARM64-based Systems, Windows 11 version 26H1 for x64-based Systems | All CVEs in KB5101649 |
| KB5101650 | Security Update | Required | Windows 11 Version 24H2 for ARM64-based Systems, Windows 11 Version 24H2 for x64-based Systems, Windows 11 Version 25H2 for ARM64-based Systems and 1 more | All CVEs in KB5101650 |
Affected products
Windows9 affected products
- Windows 11 Version 24H2 for ARM64-based Systems
- Windows 11 Version 24H2 for x64-based Systems
- Windows 11 Version 25H2 for ARM64-based Systems
- Windows 11 Version 25H2 for x64-based Systems
- Windows 11 Version 26H1 for ARM64-based Systems
- Windows 11 version 26H1 for x64-based Systems
- Windows Server 2022
- Windows Server 2025
- Windows Server 2025 (Server Core installation)