Cyber Posture

CVE-2026-20926

High

Published: 13 January 2026

Published
13 January 2026
Modified
16 January 2026
KEV Added
Patch
CVSS Score 7.5 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0005 16.3th percentile
Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-20926 is a high-severity Race Condition (CWE-362) vulnerability in Microsoft Windows 10 1607. Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 16.3th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploitation for Privilege Escalation (T1068).
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.

addresses: CWE-362

Accurate timestamps from internal clocks enable detection of race conditions by providing reliable event ordering in audit logs.

addresses: CWE-362

Coordination of concurrent security activities reduces the probability that shared resources will be accessed simultaneously without proper synchronization.

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?

Race condition in SMB Server directly enables remote exploitation for privilege escalation by a low-privileged attacker.

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

NVD Description

Concurrent execution using shared resource with improper synchronization ('race condition') in Windows SMB Server allows an authorized attacker to elevate privileges over a network.

Deeper analysisAI

CVE-2026-20926 is a race condition vulnerability (CWE-362) in the Windows SMB Server, caused by concurrent execution using a shared resource with improper synchronization. Published on 2026-01-13T18:16:19.423, it carries a CVSS v3.1 base score of 7.5 (AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H) and affects the Windows SMB Server component.

An authorized attacker with low privileges (PR:L) can exploit this vulnerability over the network (AV:N) despite high attack complexity (AC:H) and no required user interaction (UI:N). Successful exploitation enables privilege escalation, resulting in high impacts to confidentiality, integrity, and availability (C:H/I:H/A:H) within an unchanged scope (S:U).

Microsoft's update guide provides details on mitigation and patching for CVE-2026-20926, available at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20926.

Details

CWE(s)

Affected Products

microsoft
windows 10 1607
≤ 10.0.14393.8783 · ≤ 10.0.14393.8783
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 2012
all versions, r2
microsoft
windows server 2016
≤ 10.0.14393.8783
microsoft
windows server 2019
≤ 10.0.17763.8276
+3 more product configuration(s) — see NVD for full list

CVEs Like This One

CVE-2026-20919Same product: Microsoft Windows 10 1607
CVE-2026-20848Same product: Microsoft Windows 10 1607
CVE-2026-21231Same product: Microsoft Windows 10 1607
CVE-2026-20934Same product: Microsoft Windows 10 1607
CVE-2026-20921Same product: Microsoft Windows 10 1607
CVE-2026-20826Same product: Microsoft Windows 10 1607
CVE-2026-32164Same product: Microsoft Windows 10 1607
CVE-2026-20930Same product: Microsoft Windows 10 1809
CVE-2026-20866Same product: Microsoft Windows 10 1809
CVE-2026-32160Same product: Microsoft Windows 10 1809

References