CVE-2026-20826
Published: 13 January 2026
Summary
CVE-2026-20826 is a high-severity Race Condition (CWE-362) vulnerability in Microsoft Windows 10 1607. 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 7.1th 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
Directly remediates the race condition vulnerability in the TWINUI subsystem by requiring timely identification, reporting, and application of vendor patches.
Prevents unauthorized and unintended information transfer via shared system resources, directly addressing the improper synchronization exploited in this concurrent execution race condition.
Enforces least privilege to limit the potential impact and scope of local privilege escalation resulting from successful exploitation of the race condition.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Race condition in Windows TWINUI subsystem directly enables local privilege escalation from low-privileged context.
NVD Description
Concurrent execution using shared resource with improper synchronization ('race condition') in Tablet Windows User Interface (TWINUI) Subsystem allows an authorized attacker to elevate privileges locally.
Deeper analysisAI
CVE-2026-20826 is a race condition vulnerability (CWE-362), stemming from concurrent execution using a shared resource with improper synchronization in the Tablet Windows User Interface (TWINUI) Subsystem of Windows. Published on 2026-01-13, 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 impact on confidentiality, integrity, and availability.
A low-privileged local user (PR:L) can exploit this vulnerability with low attack complexity and no user interaction required. Successful exploitation enables local privilege escalation, allowing the attacker to gain higher-level access on the affected system.
Microsoft's Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20826 provides details on patches and mitigation guidance.
Details
- CWE(s)