CVE-2026-20182
Description
May 2026: This security advisory provides the details and fix information for a vulnerability that was discovered and fixed after the was disclosed in February 2026. This new advisory is for a new vulnerability in the control connection handshaking. The section of this advisory includes Show Control Connections guidance to help with system checks.
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 the 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.
Summary dbcve.org
A critical authentication bypass vulnerability exists in the peering authentication mechanism of Cisco Catalyst SD-WAN Controller, Manager, and Validator. The vulnerability allows unauthenticated remote attackers to bypass authentication during control connection handshaking and gain access as a high-privileged non-root user account. Once authenticated, attackers can leverage NETCONF access to manipulate the entire SD-WAN fabric configuration.
Mitigation
Apply the Cisco-provided security patch or upgrade to a fixed version. Verify that peering authentication is now properly enforced and that NETCONF access requires valid authentication.