CVE-2000-0621: Microsoft Outlook

High severity, CVSS 7.5. EPSS: 22.1% chance of exploitation in the next 30 days.

Microsoft Outlook 98 and 2000, and Outlook Express 4.0x and 5.0x, allow remote attackers to read files on the client's system via a malformed HTML message that stores files outside of the cache, aka the "Cache Bypass" vulnerability.

Affected products

• Microsoft Outlook: version 97 only; version 98 only; version 2000 only
• Microsoft Outlook Express: version 4.0 only; version 4.01 only; version 5.0 only; version 5.0.1 only

Published 2000-07-20. Last modified 2026-06-16.