CVE-2025-32709MicrosoftOperating systemsMay 13, 2025

Microsoft Windows Ancillary Function Driver for WinSock Use-After-Free Vulnerability

High 7.8Actively exploited

Description

Microsoft Windows Ancillary Function Driver for WinSock contains a use-after-free vulnerability that allows an authorized attacker to escalate privileges to administrator.

What to do

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Running Microsoft devices? Get an email when a new vulnerability comes out. Free, unsubscribe in one click.
Turn on Microsoft alerts

Details

Vendor
Microsoft
Product
Windows
CVE
CVE-2025-32709
Affected versions
Windows 10 Version 1507 10.0: from 10.0.10240.0 to 10.0.10240.21014 (excluded) — fixed in 10.0.10240.21014
Windows 10 Version 1607 10.0: from 10.0.14393.0 to 10.0.14393.8066 (excluded) — fixed in 10.0.14393.8066
Windows 10 Version 1809 10.0: from 10.0.17763.0 to 10.0.17763.7314 (excluded) — fixed in 10.0.17763.7314
Windows 10 Version 21H2 10.0: from 10.0.19044.0 to 10.0.19044.5854 (excluded) — fixed in 10.0.19044.5854
Windows 10 Version 22H2 10.0: from 10.0.19045.0 to 10.0.19045.5854 (excluded) — fixed in 10.0.19045.5854
Windows 11 version 22H2 10.0: from 10.0.22621.0 to 10.0.22621.5335 (excluded) — fixed in 10.0.22621.5335
Windows 11 version 22H3 10.0: from 10.0.22631.0 to 10.0.22631.5335 (excluded) — fixed in 10.0.22631.5335
Windows 11 Version 23H2 10.0: from 10.0.22631.0 to 10.0.22631.5335 (excluded) — fixed in 10.0.22631.5335
Windows 11 Version 24H2 10.0: from 10.0.26100.0 to 10.0.26100.4061 (excluded) — fixed in 10.0.26100.4061
Windows Server 2008 R2 Service Pack 1 6.1: from 6.1.7601.0 to 6.1.7601.27730 (excluded) — fixed in 6.1.7601.27730
Windows Server 2008 R2 Service Pack 1 (Server Core installat 6.1: from 6.1.7601.0 to 6.1.7601.27730 (excluded) — fixed in 6.1.7601.27730
Windows Server 2008 Service Pack 2 6.0: from 6.0.6003.0 to 6.0.6003.23317 (excluded) — fixed in 6.0.6003.23317
Windows Server 2008 Service Pack 2 (Server Core installation 6.0: from 6.0.6003.0 to 6.0.6003.23317 (excluded) — fixed in 6.0.6003.23317
Windows Server 2012 6.2: from 6.2.9200.0 to 6.2.9200.25475 (excluded) — fixed in 6.2.9200.25475
Windows Server 2012 (Server Core installation) 6.2: from 6.2.9200.0 to 6.2.9200.25475 (excluded) — fixed in 6.2.9200.25475
Windows Server 2012 R2 6.3: from 6.3.9600.0 to 6.3.9600.22577 (excluded) — fixed in 6.3.9600.22577
Windows Server 2012 R2 (Server Core installation) 6.3: from 6.3.9600.0 to 6.3.9600.22577 (excluded) — fixed in 6.3.9600.22577
Windows Server 2016 10.0: from 10.0.14393.0 to 10.0.14393.8066 (excluded) — fixed in 10.0.14393.8066
Windows Server 2016 (Server Core installation) 10.0: from 10.0.14393.0 to 10.0.14393.8066 (excluded) — fixed in 10.0.14393.8066
Windows Server 2019 10.0: from 10.0.17763.0 to 10.0.17763.7314 (excluded) — fixed in 10.0.17763.7314
Windows Server 2019 (Server Core installation) 10.0: from 10.0.17763.0 to 10.0.17763.7314 (excluded) — fixed in 10.0.17763.7314
Windows Server 2022 10.0: from 10.0.20348.0 to 10.0.20348.3692 (excluded) — fixed in 10.0.20348.3692
Windows Server 2022, 23H2 Edition (Server Core installation) 10.0: from 10.0.25398.0 to 10.0.25398.1611 (excluded) — fixed in 10.0.25398.1611
Windows Server 2025 10.0: from 10.0.26100.0 to 10.0.26100.4061 (excluded) — fixed in 10.0.26100.4061
Windows Server 2025 (Server Core installation) 10.0: from 10.0.26100.0 to 10.0.26100.4061 (excluded) — fixed in 10.0.26100.4061 (from the advisory and NVD; check the exact builds in the official advisory)
CVSS score
7.8
Actively exploited
Yes, listed in the CISA Known Exploited Vulnerabilities catalog
CISA due date
June 3, 2025 (deadline for US federal agencies: a good benchmark for you too)
Source
CISA KEV – original advisory
Published
May 13, 2025

The description and the recommended action are quoted from the public advisory; severity, exploitation status and affected versions are compiled automatically from public sources and may contain errors. The vendor's original advisory prevails: check it before taking action. This information is provided without warranty and does not replace a professional assessment.

More Microsoft advisories