High MSRC-CVE-2026-34346 1 CVE

Windows Ancillary Function Driver for WinSock Information Disclosure Vulnerability

Published Jul 14, 2026 · Updated Jul 14, 2026

Vendor: Microsoft

Summary

Impact: Information Disclosure. Microsoft rating: Important. Not known to be exploited — Exploitation Less Likely. Customer action: Required.

Details

Security updates
10.0.17763.9020 — https://support.microsoft.com/help/5099538
10.0.20348.5386 — https://support.microsoft.com/help/5099540
10.0.19044.7548 — https://support.microsoft.com/help/5099539
10.0.26100.33158 — https://support.microsoft.com/help/5099536
10.0.26200.8875 — https://support.microsoft.com/help/5101650
10.0.22631.7376 — https://support.microsoft.com/help/5099414
10.0.28000.2525 — https://support.microsoft.com/help/5101649
10.0.14393.9339 — https://support.microsoft.com/help/5099535
6.2.9200.26226 — https://support.microsoft.com/help/5099445
6.3.9600.23291 — https://support.microsoft.com/help/5099444

Vulnerabilities 1

Medium 5.5

CVE-2026-34346

Windows Ancillary Function Driver for WinSock Information Disclosure Vulnerability

Cleartext transmission of sensitive information in Windows Ancillary Function Driver for WinSock allows an authorized attacker to disclose information locally.

Microsoft Windows Server 2019 Windows Server 2019 (Server Core installation) Windows 10 Version 1809 Windows

Jul 14, 2026

Revision history

2026-07-14 #1
Information published.

References

CVE-2026-34346 Windows Ancillary Function Driver for WinSock Information Disclosure Vulnerability - HTML
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-34346
Microsoft Exploitability Index
https://www.microsoft.com/en-us/msrc/exploitability-index?rtc=1
Microsoft Support Lifecycle
https://support.microsoft.com/lifecycle
Common Vulnerability Scoring System
https://www.first.org/cvss