ACTIVELY EXPLOITED

CVE-2018-0172: Cisco IOS and IOS XE Software Improper Input Validation Vulnerability

Facts
VendorCisco
ProductIOS and 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 DHCP option 82 encapsulation functionality of Cisco IOS Software and Cisco IOS XE Software could allow for denial-of-service (DoS).

SOURCES

Other Cisco flaws

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