CVE-1999-1463: Microsoft Windows Nt

Medium severity, CVSS 5.0. EPSS: 16.6% chance of exploitation in the next 30 days.

Windows NT 4.0 before SP3 allows remote attackers to bypass firewall restrictions or cause a denial of service (crash) by sending improperly fragmented IP packets without the first fragment, which the TCP/IP stack incorrectly reassembles into a valid session.

Affected products

• Microsoft Windows Nt: up to and including 4.0

Published 1997-07-10. Last modified 2026-06-16.