CVE-2026-20844
Published: 13 January 2026
Summary
CVE-2026-20844 is a high-severity Race Condition (CWE-362) vulnerability in Microsoft Windows 10 1607. Its CVSS base score is 7.4 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 6.9th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
Threat & Defense at a Glance
Threat & Defense Details
Likely Mitigating ControlsAI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Accurate timestamps from internal clocks enable detection of race conditions by providing reliable event ordering in audit logs.
Coordination of concurrent security activities reduces the probability that shared resources will be accessed simultaneously without proper synchronization.
Use-after-free exploits that achieve arbitrary code execution are blocked or significantly hardened by non-executable pages and ASLR.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Direct local privilege escalation via exploitation of a use-after-free race condition in a Windows system component.
NVD Description
Use after free in Windows Clipboard Server allows an unauthorized attacker to elevate privileges locally.
Deeper analysisAI
CVE-2026-20844 is a use-after-free vulnerability (CWE-416), associated with a race condition (CWE-362), in the Windows Clipboard Server component of Microsoft Windows operating systems. Published on January 13, 2026, it carries a CVSS v3.1 base score of 7.4 (AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H), indicating high severity due to potential impacts on confidentiality, integrity, and availability.
The vulnerability can be exploited by an unauthorized local attacker requiring high attack complexity but no privileges, user interaction, or scope change. Successful exploitation enables local privilege escalation, allowing the attacker to gain elevated access on the affected system.
Microsoft's update guide at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20844 provides details on patches and mitigations for this issue.
Details
- CWE(s)