CVE-2019-1951: Cisco SD-WAN Firmware

Medium severity, CVSS 5.8. EPSS: 1.5% chance of exploitation in the next 30 days.

A vulnerability in the packet filtering features of Cisco SD-WAN Solution could allow an unauthenticated, remote attacker to bypass L3 and L4 traffic filters. The vulnerability is due to improper traffic filtering conditions on an affected device. An attacker could exploit this vulnerability by crafting a malicious TCP packet with specific characteristics and sending it to a target device. A successful exploit could allow the attacker to bypass the L3 and L4 traffic filters and inject an arbitrary packet in the network.

Affected products

• Cisco SD-WAN Firmware: up to and including 19.1.0

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