CVE-2026-27929
TOCTOU Race Condition in Windows LUAFV Enables Local Privilege Escalation
Publication date: 2026-04-14
Last updated on: 2026-04-22
Assigner: Microsoft Corporation
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| microsoft | windows_server_2012 | r2 |
| microsoft | windows_server_2012 | * |
| microsoft | windows_10_1607 | to 10.0.14393.9060 (exc) |
| microsoft | windows_10_1607 | to 10.0.14393.9060 (exc) |
| microsoft | windows_10_1809 | to 10.0.17763.8644 (exc) |
| microsoft | windows_10_1809 | to 10.0.17763.8644 (exc) |
| microsoft | windows_10_21h2 | to 10.0.19044.7184 (exc) |
| microsoft | windows_10_21h2 | to 10.0.19044.7184 (exc) |
| microsoft | windows_10_21h2 | to 10.0.19044.7184 (exc) |
| microsoft | windows_10_22h2 | to 10.0.19045.7184 (exc) |
| microsoft | windows_10_22h2 | to 10.0.19045.7184 (exc) |
| microsoft | windows_10_22h2 | to 10.0.19045.7184 (exc) |
| microsoft | windows_11_23h2 | to 10.0.22631.6936 (exc) |
| microsoft | windows_11_23h2 | to 10.0.22631.6936 (exc) |
| microsoft | windows_11_24h2 | to 10.0.26100.8246 (exc) |
| microsoft | windows_11_24h2 | to 10.0.26100.8246 (exc) |
| microsoft | windows_11_25h2 | to 10.0.26200.8246 (exc) |
| microsoft | windows_11_25h2 | to 10.0.26200.8246 (exc) |
| microsoft | windows_11_26h1 | to 10.0.28000.1836 (exc) |
| microsoft | windows_11_26h1 | to 10.0.28000.1836 (exc) |
| microsoft | windows_server_2016 | to 10.0.14393.9060 (exc) |
| microsoft | windows_server_2019 | to 10.0.17763.8644 (exc) |
| microsoft | windows_server_2022 | to 10.0.20348.5020 (exc) |
| microsoft | windows_server_2022_23h2 | to 10.0.25398.2274 (exc) |
| microsoft | windows_server_2025 | to 10.0.26100.32690 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-367 | The product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability is a time-of-check time-of-use (toctou) race condition found in Windows LUAFV. It allows an authorized attacker to elevate their privileges locally on the affected system.
How can this vulnerability impact me? :
An attacker who is already authorized on the system can exploit this vulnerability to gain higher privileges than intended. This elevation of privilege can lead to unauthorized access to sensitive system functions and data.
What immediate steps should I take to mitigate this vulnerability?
This vulnerability allows an authorized attacker to elevate privileges locally due to a time-of-check time-of-use (toctou) race condition in Windows LUAFV.
To mitigate this vulnerability, it is recommended to apply the security updates provided by Microsoft as soon as possible.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
This vulnerability allows an authorized attacker to elevate privileges locally on Windows systems due to a time-of-check time-of-use (toctou) race condition in Windows LUAFV.
Elevation of privilege vulnerabilities can potentially impact compliance with standards and regulations such as GDPR and HIPAA by increasing the risk of unauthorized access to sensitive data or systems.
However, the provided information does not specify direct effects or assessments related to compliance with these standards.