SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2026-45601

Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.

HIGH 7.0EPSS 0.18%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.18%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.

CVSS 3.1
7.0 HIGHCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS
0.18% probability · 8th percentile
CISA KEV
Not listed
Weakness
CWE-362, CWE-416
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 11 26h1 · microsoft/windows server 2012 · microsoft/windows server 2016 · microsoft/windows server 2019 · microsoft/windows server 2022 · microsoft/windows server 2025
Source
secure@microsoft.com

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