CVE-2008-4963: Cisco Catos

High severity, CVSS 7.1. EPSS: 1.7% chance of exploitation in the next 30 days.

Unspecified vulnerability in the VLAN Trunking Protocol (VTP) implementation on Cisco IOS and CatOS, when the VTP operating mode is not transparent, allows remote attackers to cause a denial of service (device reload or hang) via a crafted VTP packet sent to a switch interface configured as a trunk port.

Affected products

• Cisco Catos: any version
• Cisco IOS: any version

Published 2008-11-06. Last modified 2026-06-16.