PT-2026-7342 · Microsoft · Windows Ancillary Function Driver For Winsock+1

Angelboy · Published 2026-02-10 · Updated 2026-02-11 · CVE-2026-21238

Positive Technologies (AI Summary)

CVSS v3.1

7.8

High

Base vector

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

Name of the Vulnerable Software and Affected Versions Windows Ancillary Function Driver for WinSock (affected versions not specified)

Description An issue with access control in the Windows Ancillary Function Driver for WinSock can allow a local attacker to gain higher privileges on a system. This is an elevation-of-privilege issue that could affect the system.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Improper Access Control

Weakness Enumeration

CWE-284

Related Identifiers

BDU:2026-01749

CVE-2026-21238

Affected Products

Windows

Windows Ancillary Function Driver For Winsock

References · 7

• http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2026-21238 · Security Note
• https://osv.dev/vulnerability/CVE-2026-21238 · Vendor Advisory
• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21238 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-21238 · Security Note
• https://bdu.fstec.ru/vul/2026-01749 · Security Note
• https://msrc.microsoft.com/update-guide/en-US/advisory/CVE-2026-21238 · Vendor Advisory
• https://t.me/avleonovcom/1631 · Telegram Post