CVE-2026-20127: Cisco Catalyst SD-WAN Controller and Manager Authentication Bypass Vulnerability

Critical severity, CVSS 10.0. Actively exploited: in CISA KEV since 2026-02-25. EPSS: 88.5% chance of exploitation in the next 30 days.

A vulnerability in the peering authentication in Cisco Catalyst SD-WAN Controller, formerly SD-WAN vSmart, Cisco Catalyst SD-WAN Manager, formerly SD-WAN vManage, and Cisco Catalyst SD-WAN Validator, formerly SD-WAN vBond, could allow an unauthenticated, remote attacker to bypass authentication and obtain administrative privileges on an affected system. This vulnerability exists because the peering authentication mechanism in an affected system is not working properly. An attacker could exploit this vulnerability by sending crafted requests to an affected system. A successful exploit could allow the attacker to log in to an affected Cisco Catalyst SD-WAN Controller as an internal, high-privileged, non-root user account. Using this account, the attacker could access NETCONF, which would then allow the attacker to manipulate network configuration for the SD-WAN fabric. 

Affected products

• Cisco Catalyst SD-WAN Manager: before 20.9.8.2 (fixed in 20.9.8.2); from 20.11, before 20.12.5.3 (fixed in 20.12.5.3); from 20.13, before 20.15.4.2 (fixed in 20.15.4.2); from 20.16, before 20.18.2.1 (fixed in 20.18.2.1); version 20.12.6 only
• Cisco SD-WAN Vbond Orchestrator: before 20.9.8.2 (fixed in 20.9.8.2); from 20.11, before 20.12.5.3 (fixed in 20.12.5.3); from 20.13, before 20.15.4.2 (fixed in 20.15.4.2); from 20.16, before 20.18.2.1 (fixed in 20.18.2.1); version 20.12.6 only
• Cisco SD-WAN Vsmart Controller: before 20.9.8.2 (fixed in 20.9.8.2); from 20.11, before 20.12.5.3 (fixed in 20.12.5.3); from 20.13, before 20.15.4.2 (fixed in 20.15.4.2); from 20.16, before 20.18.2.1 (fixed in 20.18.2.1); version 20.12.6 only

Published 2026-02-25. Last modified 2026-06-17.