CVE-2026-20127
Description
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.
Summary dbcve.org
A critical authentication bypass vulnerability exists in the peering authentication mechanism of Cisco Catalyst SD-WAN (vSmart, vManage, vBond). The mechanism fails to properly authenticate, allowing unauthenticated remote attackers to gain high-privileged non-root user access to the SD-WAN Controller. This privileged access enables NETCONF exploitation for full network configuration manipulation of the SD-WAN fabric.
Mitigation
Apply Cisco's official patches/updates for this vulnerability to all affected SD-WAN components (vSmart, vManage, vBond). Until patches are available, restrict network access to management interfaces and monitor for unauthorized administrative access attempts.