Cyber Posture

CVE-2026-20924

High

Published: 13 January 2026

Published
13 January 2026
Modified
16 January 2026
KEV Added
Patch
CVSS Score 7.8 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
EPSS Score 0.0003 7.1th percentile
Risk Priority 16 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-20924 is a high-severity Race Condition (CWE-362) vulnerability in Microsoft Windows 10 1809. 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 SI-16 (Memory Protection) and SI-2 (Flaw Remediation).

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploitation for Privilege Escalation (T1068). What defenders deploy: see the NIST 800-53 controls recommended below.
Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

prevent

SI-2 requires timely identification, reporting, and correction of flaws like this use-after-free vulnerability via patching, directly eliminating the CVE.

prevent

SI-16 implements memory protection safeguards such as ASLR and DEP that directly mitigate exploitation of use-after-free vulnerabilities.

prevent

AC-6 enforces least privilege, limiting the impact of local privilege escalation by restricting unnecessary access in Windows Management Services.

MITRE ATT&CK Enterprise TechniquesAI

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
Why these techniques?

Use-after-free in Windows Management Services directly enables local privilege escalation via memory corruption exploitation (T1068).

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

NVD Description

Use after free in Windows Management Services allows an authorized attacker to elevate privileges locally.

Deeper analysisAI

CVE-2026-20924 is a use-after-free vulnerability in Windows Management Services, associated with CWE-416 (use after free) and CWE-362 (concurrent execution, sharing resources). Published on 2026-01-13, it carries a CVSS v3.1 base score of 7.8 (AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H), indicating high severity due to its potential for significant impact despite requiring local access and high attack complexity.

The vulnerability can be exploited by an authorized local attacker possessing low privileges. Exploitation requires high attack complexity and no user interaction, but successful attacks change scope and grant high confidentiality, integrity, and availability impacts, enabling local privilege escalation.

The Microsoft Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20924 provides guidance on mitigations and available patches.

Details

CWE(s)

Affected Products

microsoft
windows 10 1809
≤ 10.0.17763.8276 · ≤ 10.0.17763.8276
microsoft
windows 10 21h2
≤ 10.0.19044.6809
microsoft
windows 10 22h2
≤ 10.0.19045.6809
microsoft
windows 11 23h2
≤ 10.0.22631.6491
microsoft
windows 11 24h2
≤ 10.0.26100.7623
microsoft
windows 11 25h2
≤ 10.0.26200.7623
microsoft
windows server 2019
≤ 10.0.17763.8276
microsoft
windows server 2022
≤ 10.0.20348.4648
microsoft
windows server 2022 23h2
≤ 10.0.25398.2092
microsoft
windows server 2025
≤ 10.0.26100.32230

CVEs Like This One

CVE-2026-20858Same product: Microsoft Windows 10 1809
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CVE-2026-20877Same product: Microsoft Windows 10 1809
CVE-2026-32163Same product: Microsoft Windows 10 1809
CVE-2026-27927Same product: Microsoft Windows 10 1809
CVE-2026-32165Same product: Microsoft Windows 10 1809
CVE-2026-32158Same product: Microsoft Windows 10 1809
CVE-2026-32159Same product: Microsoft Windows 10 1809

References