CVE-2015-6278: Cisco IOS

High severity, CVSS 7.8. EPSS: 3.2% chance of exploitation in the next 30 days.

The IPv6 snooping functionality in the first-hop security subsystem in Cisco IOS 12.2, 15.0, 15.1, 15.2, 15.3, 15.4, and 15.5 and IOS XE 3.2SE, 3.3SE, 3.3XO, 3.4SG, 3.5E, and 3.6E before 3.6.3E; 3.7E before 3.7.2E; 3.9S and 3.10S before 3.10.6S; 3.11S before 3.11.4S; 3.12S and 3.13S before 3.13.3S; and 3.14S before 3.14.2S does not properly implement the Control Plane Protection (aka CPPr) feature, which allows remote attackers to cause a denial of service (device reload) via a flood of ND packets, aka Bug ID CSCus19794.

Affected products

• Cisco IOS: version 12.2(50)sy only; version 12.2(50)sy1 only; version 12.2(50)sy2 only; version 12.2(50)sy3 only; version 12.2(50)sy4 only; version 15.0(1)ex only; …
• Cisco IOS XE: version 3.2se.0 only; version 3.2se.1 only; version 3.2se.2 only; version 3.2se.3 only; version 3.3se.0 only; version 3.3se.1 only; …

Published 2015-09-28. Last modified 2026-06-17.