CVE-1999-1189: Netscape Communicator

High severity, CVSS 7.5. EPSS: 2.5% chance of exploitation in the next 30 days.

Buffer overflow in Netscape Navigator/Communicator 4.7 for Windows 95 and Windows 98 allows remote attackers to cause a denial of service, and possibly execute arbitrary commands, via a long argument after the ? character in a URL that references an .asp, .cgi, .html, or .pl file.

Affected products

• Netscape Communicator: version 4.7 only
• Netscape Navigator: version 4.7 only

Published 1999-11-24. Last modified 2026-06-16.