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CVE-2026-21241

Severity CVSS v4.0:
Pending analysis
Type:
CWE-416 Use After Free
Publication date:
10/02/2026
Last modified:
11/02/2026

Description

Use after free in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.

Impact

Vector 3.x
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H CVSS v3.1 Severity and Metrics:

Base Score: 7.00 HIGH
Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack Vector (AV): Local
Attack Complexity (AC): High
Privileges Required (PR): Low
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): High
Integrity (I): High
Availability (A): High

Base Score 3.x
7.00
Severity 3.x
HIGH

Vulnerable products and versions

CPE From Up to
cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:arm64:* 10.0.22631.6649 (excluding)
cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:x64:* 10.0.22631.6649 (excluding)
cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:arm64:* 10.0.26100.7781 (excluding)
cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:x64:* 10.0.26100.7781 (excluding)
cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:arm64:* 10.0.26200.7781 (excluding)
cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:x64:* 10.0.26200.7781 (excluding)
cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:* 10.0.20348.4711 (excluding)
cpe:2.3:o:microsoft:windows_server_2022_23h2:*:*:*:*:*:*:*:* 10.0.25398.2149 (excluding)
cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:* 10.0.26100.32313 (excluding)

To consult the complete list of CPE names with products and versions, see this page


References to Advisories, Solutions, and Tools