VulnerabilityAnalyzed

CVE-2026-20927

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

MEDIUM 5.3EPSS 0.92%

Does this matter?

Lower severity and a low EPSS score (0.92%). Track it; it rarely justifies an emergency change on its own.

Description

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

CVSS 3.1: 5.3 MEDIUMCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS: 0.92% probability · 58th percentile
CISA KEV: Not listed
Weakness: CWE-362
Affected: microsoft/windows 10 1607 · microsoft/windows 10 1809 · microsoft/windows 10 21h2 · microsoft/windows 10 22h2 · microsoft/windows 11 23h2 · microsoft/windows 11 24h2 · microsoft/windows 11 25h2 · microsoft/windows server 2008 · microsoft/windows server 2012 · microsoft/windows server 2016 · microsoft/windows server 2019 · microsoft/windows server 2022 · microsoft/windows server 2022 23h2 · microsoft/windows server 2025
Source: secure@microsoft.com

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20927Vendor Advisory

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.