CVE-2006-4774: Cisco IOS

High severity, CVSS 7.8. EPSS: 5% chance of exploitation in the next 30 days.

The VLAN Trunking Protocol (VTP) feature in Cisco IOS 12.1(19) allows remote attackers to cause a denial of service by sending a VTP version 1 summary frame with a VTP version field value of 2.

Affected products

• Cisco IOS: version 12.1(19) only

Published 2006-09-14. Last modified 2026-06-16.