What is the CVSS score of CVE-2025-49661?

CVE-2025-49661 has a CVSS 3.1 base score of 7.8 (High). CVSS vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.1%.

Which versions of Windows are affected by CVE-2025-49661?

CVE-2025-49661 is a privilege escalation vulnerability in Windows Ancillary Function Driver for WinSock that affects authorized users who can escalate their privileges to system level, potentially…. A patch is available.

How to fix or mitigate CVE-2025-49661?

Within 24 hours: Identify all Windows systems running affected Ancillary Function Driver versions and assess which systems are accessible to authenticated users. Within 7 days: Deploy vendor-released patch to non-production environments and validate compatibility with line-of-business applications. Within 30 days: Complete patch deployment to all production Windows systems, beginning with high-sensitivity environments (administrative workstations, domain controllers, sensitive servers).

Windows CVE-2025-49661

EUVD-2025-20645 HIGH

Untrusted Pointer Dereference (CWE-822)

2025-07-08 secure@microsoft.com

Windows Information Disclosure Microsoft Windows 10 1507 Windows 10 1607 Windows 10 1809 Windows 10 21h2 Windows 10 22h2 Windows 11 22h2 Windows 11 23h2 Windows 11 24h2 Windows Server 2008 Windows Server 2012 Windows Server 2016 Windows Server 2019 Windows Server 2022 Windows Server 2022 23h2 Windows Server 2025

7.8

CVSS 3.1

CVSS VectorNVD

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Analysis Updated

Apr 16, 2026 - 06:31 EUVD-patch-fix

executive_summary

Re-analysis Queued

Apr 16, 2026 - 05:29 backfill_euvd_patch

patch_released

Patch available

Apr 16, 2026 - 05:29 EUVD

10.0.19045.6093,10.0.22621.5624,10.0.19044.6093

EUVD ID Assigned

Mar 16, 2026 - 04:21 euvd

EUVD-2025-20645

Analysis Generated

Mar 16, 2026 - 04:21 vuln.today

CVE Published

Jul 08, 2025 - 17:15 nvd

HIGH 7.8

DescriptionNVD

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

AnalysisAI

A privilege escalation vulnerability in Untrusted pointer dereference in Windows Ancillary Function Driver for WinSock (CVSS 7.8) that allows an authorized attacker. High severity vulnerability requiring prompt remediation.

Technical ContextAI

Vulnerability type: privilege escalation. CVSS 7.8 indicates high severity. Affects Untrusted pointer dereference in Windows Ancillary Function Driver for WinSock.