Executive brief
A security flaw in Windows Cryptographic Services could allow an attacker to bypass security protections by using improperly validated digital certificates. This component is responsible for handling secure communications and verifying the identity of software and websites. If exploited, an attacker could potentially trick a user into trusting a malicious connection or file, though the attack requires specific user interaction and complex timing to succeed.
Technical details
A vulnerability classified as Improper Certificate Validation (CWE-295) exists in Windows Cryptographic Services. The flaw allows an unauthenticated attacker to bypass security features by presenting a specially crafted certificate that the system fails to validate correctly. The attack vector is network-based, but it carries high complexity (AC:H) and requires user interaction (UI:R). Successful exploitation could lead to a partial loss of confidentiality and integrity. Microsoft has released security updates to address this issue across affected versions of Windows 10, 11, and Windows Server.
Affected products
- Microsoft Windows 10 Version 21H2 10.0.19044.0 to 10.0.19044.7548
- Microsoft Windows 10 Version 22H2 10.0.19045.0 to 10.0.19045.7548
- Microsoft Windows 11 Version 24H2 10.0.26100.0 to 10.0.26100.8875
- Microsoft Windows 11 Version 25H2 10.0.26200.0 to 10.0.26200.8875
- Microsoft Windows 11 version 26H1 10.0.28000.0 to 10.0.28000.2269
- Microsoft Windows Server 2022 10.0.20348.0 to 10.0.20348.5386
- Microsoft Windows Server 2025 10.0.26100.0 to 10.0.26100.33158
Timeline
- 2026-07-14: advisory: Initial publication by Microsoft and NVD
- 2026-07-14: patched: Security updates released by Microsoft