CVE-2006-6696: Microsoft Windows 2000

Medium severity, CVSS 6.9. EPSS: 3.4% chance of exploitation in the next 30 days.

Double free vulnerability in Microsoft Windows 2000, XP, 2003, and Vista allows local users to gain privileges by calling the MessageBox function with a MB_SERVICE_NOTIFICATION message with crafted data, which sends a HardError message to Client/Server Runtime Server Subsystem (CSRSS) process, which is not properly handled when invoking the UserHardError and GetHardErrorText functions in WINSRV.DLL.

Affected products

• Microsoft Windows 2000: any version
• Microsoft Windows 2003 Server: version datacenter_edition only; version enterprise_edition only; version sp1 only; version standard only; version web only
• Microsoft Windows Vista: any version
• Microsoft Windows XP: any version

Published 2006-12-22. Last modified 2026-06-16.