CVE-1999-1094: Microsoft Internet Explorer

High severity, CVSS 7.5. EPSS: 18.4% chance of exploitation in the next 30 days.

Buffer overflow in Internet Explorer 4.01 and earlier allows remote attackers to execute arbitrary commands via a long URL with the "mk:" protocol, aka the "MK Overrun security issue."

Affected products

• Microsoft Internet Explorer: up to and including 4.0.1

Published 1999-12-31. Last modified 2026-06-16.