EUVD-2026-22623
GHSA-gjhf-vqgr-hxwj
Severity by source
AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Primary rating from Vendor (microsoft).
CVSS VectorVendor: microsoft
Lifecycle Timeline
6DescriptionCVE.org
Use after free in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.
AnalysisAI
Local privilege escalation in Windows Ancillary Function Driver for WinSock (AFD.sys) affects all supported Windows 10, Windows 11, and Windows Server versions from 2012 through 2025. The CWE-416 use-after-free memory corruption flaw allows low-privileged authenticated attackers with local access to elevate to SYSTEM privileges, achieving complete control over confidentiality, integrity, and availability. SSVC framework rates this as non-automatable with total technical impact. No public exploit
Technical ContextAI
The Windows Ancillary Function Driver for WinSock (AFD.sys) is a kernel-mode component that provides socket support and network protocol handling for Windows Sockets (WinSock) API. This CWE-416 use-after-free vulnerability occurs when the driver improperly manages memory object lifecycle, allowing a reference to freed memory to be subsequently dereferenced. In kernel-mode drivers, use-after-free conditions are particularly dangerous because they enable attackers to control freed memory allocation and potentially redirect execution flow or manipulate kernel data structures. The affected CPE strings identify this as impacting the full spectrum of modern Windows operating systems including client editions (Windows 10 versions 1607/1809/21H2/22H2, Windows 11 versions 22H3/23H2/24H2/25H2/26H1) and server platforms (Windows Server 2012/2012 R2/2016/2019/2022/2025 including Server Core installations). The local attack vector (AV:L) combined with kernel-level driver vulnerability makes this a classic Windows privilege escalation primitive.
RemediationAI
Apply vendor-released security updates immediately through Windows Update or Microsoft Update Catalog. Patch to the following minimum versions: Windows Server 2012 to 6.2.9200.26026 or later, Windows Server 2012 R2 to 6.3.9600.23132 or later, Windows 10 Version 1607 and Server 2016 to 10.0.14393.9060 or later, Windows 10 Version 1809 and Server 2019 to 10.0.17763.8644 or later, Windows 10 Version 21H2 to 10.0.19044.7184 or later, Windows 10 Version 22H2 to 10.0.19045.7184 or later, Windows 11 versions 22H3/23H2 to 10.0.22631.6936 or later, Windows 11 Version 24H2 and Server 2025 to 10.0.26100.32690 or later, Windows 11 Version 25H2 to 10.0.26200.8246 or later, Windows 11 Version 26H1 to 10.0.28000.1836 or later, Windows Server 2022 to 10.0.20348.5020 or later, and Server 2022 23H2 Edition to 10.0.25398.2274 or later. Download patches from Microsoft Security Response Center at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-33100. No effective workarounds exist for kernel-mode driver vulnerabilities beyond restricting local logon access to trusted users only. Prioritize patching systems with multiple local user accounts or those in shared/multi-tenant environments.
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Same weakness CWE-416 – Use After Free
View allSame technique Denial Of Service
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External POC / Exploit Code
Leaving vuln.today