PT-2026-2705 · Microsoft · Windows Ancillary Function Driver For Winsock+1

Angelboy · Published 2026-01-13 · Updated 2026-01-15 · CVE-2026-20860

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 A type confusion issue exists in the Windows Ancillary Function Driver for WinSock. This allows a locally authorized attacker to gain elevated privileges.

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

Type Confusion

Weakness Enumeration

CWE-843

Related Identifiers

BDU:2026-00436

CVE-2026-20860

Affected Products

Windows

Windows Ancillary Function Driver For Winsock

References · 7

• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20860 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-20860 · Security Note
• https://osv.dev/vulnerability/CVE-2026-20860 · Vendor Advisory
• https://msrc.microsoft.com/update-guide/en-US/advisory/CVE-2026-20860 · Vendor Advisory
• http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2026-20860 · Security Note
• https://bdu.fstec.ru/vul/2026-00436 · Security Note
• https://twitter.com/CVEnew/status/2011759666410176570 · Twitter Post