CVE-2015-6429: Cisco IOS

Medium severity, CVSS 5.0. EPSS: 1.7% chance of exploitation in the next 30 days.

The IKEv1 state machine in Cisco IOS 15.4 through 15.6 and IOS XE 3.15 through 3.17 allows remote attackers to cause a denial of service (IPsec connection termination) via a crafted IKEv1 packet to a tunnel endpoint, aka Bug ID CSCuw08236.

Affected products

• Cisco IOS: version 15.4(3)s only; version 15.5(1)s only; version 15.5(1)t only; version 15.5(2)s only; version 15.5(2)t only; version 15.5(3)m only; …
• Cisco IOS XE: version 3.15s.0 only; version 3.15s.1 only; version 3.15s.2 only; version 3.16s.0 only; version 3.16s.1 only; version 3.17s.0 only; …

Published 2015-12-19. Last modified 2026-06-17.