CVE-2026-20927CWE-362

CVE-2026-20927

Medium · published January 13, 2026

CVSS v3.1
5.3
EPSS
1%
Percentile
59.6
In the wild
Unconfirmed
What it is

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

The record
Technical detail
CVSS v3.1
5.3 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.00909 · 59.6th percentile
Weakness
CWE-362 · Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
Published
2026-01-13T23:16Z
Affected products (19)
ProductVersionsFixed in
microsoft/windows_10_1607< 10.0.14393.878310.0.14393.8783
microsoft/windows_10_1607< 10.0.14393.878310.0.14393.8783
microsoft/windows_10_1809< 10.0.17763.827610.0.17763.8276
microsoft/windows_10_1809< 10.0.17763.827610.0.17763.8276
microsoft/windows_10_21h2< 10.0.19044.680910.0.19044.6809
microsoft/windows_10_22h2< 10.0.19045.680910.0.19045.6809
microsoft/windows_11_23h2< 10.0.22631.649110.0.22631.6491
microsoft/windows_11_24h2< 10.0.26100.762310.0.26100.7623
microsoft/windows_11_25h2< 10.0.26200.762310.0.26200.7623
microsoft/windows_server_2008all versions—
microsoft/windows_server_2008all versions—
microsoft/windows_server_2008all versions—
microsoft/windows_server_2012all versions—
microsoft/windows_server_2012all versions—
microsoft/windows_server_2016< 10.0.14393.878310.0.14393.8783
microsoft/windows_server_2019< 10.0.17763.827610.0.17763.8276
microsoft/windows_server_2022< 10.0.20348.464810.0.20348.4648
microsoft/windows_server_2022_23h2< 10.0.25398.209210.0.25398.2092
microsoft/windows_server_2025< 10.0.26100.3223010.0.26100.32230
References (1)
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20927 · [email protected]
EPSS history
Timeline
  • 13 JAN 17:56Z
    Windows SMB Server Denial of Service Vulnerability
    cvelistv5