CVE-2019-1964: Cisco NX-OS

High severity, CVSS 7.5. EPSS: 2% chance of exploitation in the next 30 days.

A vulnerability in the IPv6 traffic processing of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause an unexpected restart of the netstack process on an affected device. The vulnerability is due to improper validation of IPv6 traffic sent through an affected device. An attacker could exploit this vulnerability by sending a malformed IPv6 packet through an affected device. A successful exploit could allow the attacker to cause a denial of service (DoS) condition while the netstack process restarts. A sustained attack could lead to a reboot of the device.

Affected products

• Cisco NX-OS: from 8.1, before 8.2\(3\) (fixed in 8.2\(3\)); from 8.3, before 8.4 (fixed in 8.4)

Published 2019-08-28. Last modified 2026-06-17.