CVE-2001-0904: Microsoft Internet Explorer

Medium severity, CVSS 5.0. EPSS: 7% chance of exploitation in the next 30 days.

Internet Explorer 5.5 and 6 with the Q312461 (MS01-055) patch modifies the HTTP_USER_AGENT (UserAgent) information that indicates that the patch has been installed, which could allow remote malicious web sites to more easily identify and exploit vulnerable clients.

Affected products

• Microsoft Internet Explorer: version 5.5 only; version 6.0 only

Published 2001-11-20. Last modified 2026-06-16.