Windows CVE-2026-21239
HIGHCVSS VectorNVD
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Lifecycle Timeline
2DescriptionNVD
Heap-based buffer overflow in Windows Kernel allows an authorized attacker to elevate privileges locally.
AnalysisAI
Privilege escalation via heap buffer overflow in Windows Kernel (Windows 10 21H2, Windows Server 2016) allows authenticated local users to gain elevated system privileges. The vulnerability requires local access and user-level permissions, making it exploitable by authorized account holders to bypass security boundaries. …
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RemediationAI
Within 24 hours: Inventory all Windows systems running affected kernel versions and assess exposure scope; initiate incident response protocol and establish monitoring for exploitation attempts. Within 7 days: Implement access controls limiting local system access, disable unnecessary user privileges, and deploy endpoint detection tools to monitor for suspicious privilege escalation activity. …
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