CVE-2026-24293: Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-03-10 · updated 2026-06-19
Weakness: CWE-476

Description

Null pointer dereference in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.

Affected products

Microsoft Windows 10: before 10.0.19044.7058 — fixed in 10.0.19044.7058
Microsoft Windows 10: before 10.0.19045.7058 — fixed in 10.0.19045.7058
Microsoft Windows 11: before 10.0.22631.6783 — fixed in 10.0.22631.6783
Microsoft Windows 11: before 10.0.26100.7979 — fixed in 10.0.26100.7979
Microsoft Windows 11 25H2: before 10.0.26200.7979 — fixed in 10.0.26200.7979
Microsoft Windows 11 version 26H1: before 10.0.28000.1719 — fixed in 10.0.28000.1719
Microsoft Windows Server 2022: before 10.0.20348.4830 — fixed in 10.0.20348.4830
Microsoft Windows Server 2022, 23H2 Edition (Server Core installation): before 10.0.25398.2207 — fixed in 10.0.25398.2207
Microsoft Windows Server 2025: before 10.0.26100.32463 — fixed in 10.0.26100.32463
Microsoft Windows 10: from 10.0.19044.0 before 10.0.19044.7058 — fixed in 10.0.19044.7058
Microsoft Windows 10: from 10.0.19045.0 before 10.0.19045.7058 — fixed in 10.0.19045.7058
Microsoft Windows 11: from 10.0.22631.0 before 10.0.22631.6783 — fixed in 10.0.22631.6783
Microsoft Windows 11: from 10.0.26100.0 before 10.0.26100.8037 — fixed in 10.0.26100.8037
Microsoft Windows 11 25H2: from 10.0.26200.0 before 10.0.26200.8037 — fixed in 10.0.26200.8037
Microsoft Windows 11 version 26H1: from 10.0.28000.0 before 10.0.28000.1719 — fixed in 10.0.28000.1719
Microsoft Windows Server 2022: from 10.0.20348.0 before 10.0.20348.4893 — fixed in 10.0.20348.4893
Microsoft Windows Server 2022, 23H2 Edition (Server Core installation): from 10.0.25398.0 before 10.0.25398.2207 — fixed in 10.0.25398.2207
Microsoft Windows Server 2025: from 10.0.26100.0 before 10.0.26100.32522 — fixed in 10.0.26100.32522

How to fix

Upgrade to a fixed version: Microsoft Windows 10 10.0.19044.7058; Microsoft Windows 10 10.0.19045.7058; Microsoft Windows 11 10.0.22631.6783; Microsoft Windows 11 10.0.26100.7979; Microsoft Windows 11 25H2 10.0.26200.7979; Microsoft Windows 11 version 26H1 10.0.28000.1719; Microsoft Windows Server 2022 10.0.20348.4830; Microsoft Windows Server 2022, 23H2 Edition (Server Core installation) 10.0.25398.2207; Microsoft Windows Server 2025 10.0.26100.32463; Microsoft Windows 10 10.0.19044.7058; Microsoft Windows 10 10.0.19045.7058; Microsoft Windows 11 10.0.22631.6783. Check the vendor advisory for mitigations.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-24293

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