CVE-2019-16027: Cisco IOS XR

Medium severity, CVSS 6.5. EPSS: 1.5% chance of exploitation in the next 30 days.

A vulnerability in the implementation of the Intermediate System–to–Intermediate System (IS–IS) routing protocol functionality in Cisco IOS XR Software could allow an authenticated, remote attacker to cause a denial of service (DoS) condition in the IS–IS process. The vulnerability is due to improper handling of a Simple Network Management Protocol (SNMP) request for specific Object Identifiers (OIDs) by the IS–IS process. An attacker could exploit this vulnerability by sending a crafted SNMP request to the affected device. A successful exploit could allow the attacker to cause a DoS condition in the IS–IS process.

Affected products

• Cisco IOS XR: version 4.3.2 only; version 5.2.5 only; version 6.2.2 only; version 6.2.3 only; version 6.2.25 only; version 6.3.3 only; …

Published 2020-01-26. Last modified 2026-06-17.