CVE-2006-0340: Cisco IOS

High severity, CVSS 7.1. EPSS: 2.7% chance of exploitation in the next 30 days.

Unspecified vulnerability in Stack Group Bidding Protocol (SGBP) support in Cisco IOS 12.0 through 12.4 running on various Cisco products, when SGBP is enabled, allows remote attackers on the local network to cause a denial of service (device hang and network traffic loss) via a crafted UDP packet to port 9900.

Affected products

• Cisco IOS: version 12.0 only; version 12.0s only; version 12.0sc only; version 12.0t only; version 12.0xa only; version 12.0xc only; …

Published 2006-01-21. Last modified 2026-06-16.