ACTIVELY EXPLOITED

CVE-2018-0159: Cisco IOS and XE Software Internet Key Exchange Version 1 Denial-of-Service Vulnerability

Facts
VendorCisco
ProductIOS Software and Cisco IOS XE Software
Actively exploitedYes
Added to CISA KEV3 Mar 2022
CISA federal deadline17 Mar 2022
Weakness (CWE)CWE-20

Required action (CISA's text)

Apply updates per vendor instructions.

Description (NVD)

A vulnerability in the implementation of Internet Key Exchange Version 1 (IKEv1) functionality in Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial-of-service (DoS) condition.

SOURCES

Other Cisco flaws

Data from NVD, CISA KEV, FIRST EPSS and vendor advisories. Updated 10 Nov 2026.