CVE-2025-27475: Windows Update Stack Elevation of Privilege Vulnerability

Severity: high (CVSS 7.0 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-04-08 · updated 2026-08-10
Weakness: CWE-591

Description

Sensitive data storage in improperly locked memory in Windows Update Stack allows an authorized attacker to elevate privileges locally.

Affected products

Microsoft Windows 11: before 10.0.22621.5189 — fixed in 10.0.22621.5189
Microsoft Windows 11: before 10.0.22631.5189 — fixed in 10.0.22631.5189
Microsoft Windows 11: before 10.0.26100.3775 — fixed in 10.0.26100.3775
Microsoft Windows 11: from 10.0.22621.0 before 10.0.22621.5189 — fixed in 10.0.22621.5189
Microsoft Windows 11 version 22H3: from 10.0.22631.0 before 10.0.22631.5189 — fixed in 10.0.22631.5189
Microsoft Windows 11: from 10.0.22631.0 before 10.0.22631.5189 — fixed in 10.0.22631.5189
Microsoft Windows 11: from 10.0.26100.0 before 10.0.26100.3775 — fixed in 10.0.26100.3775

How to fix

Upgrade to a fixed version: Microsoft Windows 11 10.0.22621.5189; Microsoft Windows 11 10.0.22631.5189; Microsoft Windows 11 10.0.26100.3775; Microsoft Windows 11 10.0.22621.5189; Microsoft Windows 11 version 22H3 10.0.22631.5189; Microsoft Windows 11 10.0.22631.5189; Microsoft Windows 11 10.0.26100.3775. Check the vendor advisory for mitigations.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-27475

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