SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2026-42900

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

HIGH 8.1EPSS 0.54%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.54%). 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 App Store allows an unauthorized attacker to elevate privileges over a network.

CVSS 3.1
8.1 HIGHCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
0.54% probability · 44th 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 24h2 · microsoft/windows 11 25h2 · microsoft/windows 11 26h1 · 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.