CVE-2025-27729: Windows Shell Remote Code Execution Vulnerability

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.8% 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-416

Description

Use after free in Windows Shell allows an unauthorized attacker to execute code locally.

Affected products

Microsoft Windows 10: before 10.0.19044.5737 — fixed in 10.0.19044.5737
Microsoft Windows 10: before 10.0.19045.5737 — fixed in 10.0.19045.5737
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 Server 2025: before 10.0.26100.3775 — fixed in 10.0.26100.3775
Microsoft Windows 10: from 10.0.19044.0 before 10.0.19044.5737 — fixed in 10.0.19044.5737
Microsoft Windows 10: from 10.0.19045.0 before 10.0.19045.5737 — fixed in 10.0.19045.5737
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
Microsoft Windows Server 2025: 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 10 10.0.19044.5737; Microsoft Windows 10 10.0.19045.5737; Microsoft Windows 11 10.0.22621.5189; Microsoft Windows 11 10.0.22631.5189; Microsoft Windows 11 10.0.26100.3775; Microsoft Windows Server 2025 10.0.26100.3775; Microsoft Windows 10 10.0.19044.5737; Microsoft Windows 10 10.0.19045.5737; 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-2025-27729

Get alerted when CVE-2025-27729 or the next vulnerability affects your stack