CVE-2026-55144 in Windows
Summary
by MITRE • 07/14/2026
Missing cryptographic step in Windows CryptoAPI allows an authorized attacker to perform tampering locally.
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Analysis
by VulDB Data Team • 07/14/2026
This vulnerability represents a critical weakness in the Windows CryptoAPI implementation that enables authenticated local attackers to manipulate cryptographic operations without proper validation. The flaw occurs when the cryptographic verification step is omitted during certificate processing, allowing malicious actors with local access to craft forged certificates or modify existing ones. This issue stems from insufficient input validation and missing integrity checks within the cryptographic pipeline, creating an attack surface where legitimate users can exploit the absence of proper cryptographic safeguards.
The technical implementation involves a failure in the certificate trust verification process where Windows CryptoAPI does not adequately validate digital signatures or cryptographic hashes before accepting certificate chains. This weakness specifically affects the certificate validation routines that should enforce cryptographic integrity checks, enabling attackers to bypass security controls designed to prevent unauthorized certificate modifications. The vulnerability manifests when local users leverage their authenticated access to manipulate certificate data structures without triggering the required cryptographic verification mechanisms that would normally detect such tampering.
Operational impact of this vulnerability extends beyond simple privilege escalation as it fundamentally undermines the trust model that Windows relies upon for secure communications and authentication. Attackers can exploit this weakness to create fraudulent certificates that appear legitimate to the system, potentially enabling man-in-the-middle attacks, credential theft, or unauthorized access to protected resources. The local nature of the attack means that compromise can occur through various vectors including legitimate user accounts, service accounts, or even compromised administrative credentials, making detection particularly challenging since the activities may appear normal from a network monitoring perspective.
Organizations should implement immediate mitigations including patching affected Windows versions, implementing enhanced monitoring for certificate-related activities, and reviewing local access controls to minimize potential attack surfaces. The vulnerability aligns with CWE-310 and CWE-311 classifications related to cryptographic issues and missing encryption steps. From an ATT&CK perspective, this weakness maps to T1552.001 (Credentials in Files) and T1078.004 (Valid Accounts: Cloud Accounts) as attackers can leverage local access to manipulate certificate trust relationships. Additional protective measures include implementing certificate pinning mechanisms, deploying extended validation certificates, and establishing robust audit trails for cryptographic operations to detect unauthorized modifications that may occur through this vulnerability.