CVE-2026-27922
Use-After-Free in Windows WinSock Driver 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-416 | The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer. |
Attack-Flow Graph
AI Powered Q&A
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
The provided information does not specify how this vulnerability affects compliance with common standards and regulations such as GDPR or HIPAA.
Can you explain this vulnerability to me?
This vulnerability is a use after free issue in the Windows Ancillary Function Driver for WinSock. It allows an authorized attacker to elevate their privileges locally on the affected system.
How can this vulnerability impact me? :
The impact of this vulnerability is that an authorized attacker can gain elevated privileges on the local system. This means the attacker could perform actions with higher permissions than originally granted, potentially compromising system security.
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability, it is important to apply the security updates provided by Microsoft for the Windows Ancillary Function Driver for WinSock as soon as they become available.
Since this vulnerability allows local privilege escalation, limiting user privileges and ensuring that only authorized users have access to the affected system can help reduce risk.