CVE-2001-0664: Microsoft Internet Explorer

High severity, CVSS 7.5. EPSS: 18.2% chance of exploitation in the next 30 days.

Internet Explorer 5.5 and 5.01 allows remote attackers to bypass security restrictions via malformed URLs that contain dotless IP addresses, which causes Internet Explorer to process the page in the Intranet Zone, which may have fewer security restrictions, aka the "Zone Spoofing vulnerability."

Affected products

• Microsoft Internet Explorer: version 5.01 only; version 5.5 only

Published 2001-10-30. Last modified 2026-06-16.