CVE-2026-27918
Published: 14 April 2026
Summary
CVE-2026-27918 is a high-severity Race Condition (CWE-362) vulnerability in Microsoft Windows 10 21H2. Its CVSS base score is 7.8 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 12.4th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified are NIST 800-53 SC-4 (Information in Shared System Resources) and SI-2 (Flaw Remediation).
Threat & Defense at a Glance
Threat & Defense Details
Mitigating Controls (NIST 800-53 r5)AI
Timely application of Microsoft patches directly remediates the race condition vulnerability in Windows Shell, preventing local privilege escalation.
Protects information in shared system resources from unauthorized access or transfer, directly mitigating the improper synchronization leading to the race condition exploit.
Enforces least privilege for local users and processes, limiting the potential impact and success of privilege escalation via the race condition.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Local race condition in Windows Shell directly enables exploitation for privilege escalation (T1068) from low-privileged context without user interaction.
NVD Description
Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Shell allows an authorized attacker to elevate privileges locally.
Deeper analysisAI
CVE-2026-27918 is a race condition vulnerability (CWE-362) stemming from concurrent execution using a shared resource with improper synchronization in the Windows Shell. Published on 2026-04-14, it carries a CVSS v3.1 base score of 7.8 (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H), indicating high severity with significant impacts on confidentiality, integrity, and availability.
A local attacker with low privileges (PR:L) can exploit this vulnerability due to its low attack complexity (AC:L) and lack of user interaction requirement (UI:N). Successful exploitation enables privilege escalation on the affected Windows system, potentially granting the attacker high-level access and control over the machine.
Microsoft provides details on this vulnerability, including patch information and mitigation guidance, in their Security Update Guide at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-27918. Security practitioners should consult this advisory for deployment instructions.
Details
- CWE(s)