CVE-2025-21204

high-risk

Published 2025-04-08

Improper link resolution before file access ('link following') in Windows Update Stack allows an authorized attacker to elevate privileges locally.

Do I need to act?

7.3% chance of exploitation in next 30 days

EPSS score — moderate exploit probability

Not on CISA KEV list

No confirmed active exploitation reported to CISA

Patch status unknown

Check vendor advisories for fix availability and mitigation guidance

CVSS 7.8/10 High

LOCAL / LOW complexity

Windows 10 1507

Windows 10 1607

Windows 10 1809

Windows 10 21H2

Windows 10 22H2

Windows 11 22H2

Windows 11 23H2

Windows 11 24H2

Windows Server 2008

Windows Server 2012

Windows Server 2016

Windows Server 2019

Windows Server 2022

Windows Server 2022 23H2

Microsoft

Vendor Advisory https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21204

Tool Signature https://www.vicarius.io/vsociety/posts/cve-2025-21204-privilege-elevation-vulner...

Mitigation https://www.vicarius.io/vsociety/posts/cve-2025-21204-privilege-elevation-vulner...

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high-risk

Severity 24/34 · High

Exploitability 9/34 · Low

Exposure 20/34 · Moderate