CVE-2026-20127: Cisco Catalyst SD-WAN Controller and Manager Authentication Bypass Vulnerability
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.
Other sources
Cisco Catalyst SD-WAN Controller, formerly SD-WAN vSmart, and Cisco Catalyst SD-WAN Manager, formerly SD-WAN vManage, contain an authentication bypass vulnerability 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.
— CISA
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-20127?
The severity of CVE-2026-20127 is classified as high due to its potential for allowing unauthenticated remote access.
How do I fix CVE-2026-20127?
To mitigate CVE-2026-20127, users should apply the latest updates and security patches provided by Cisco.
Which products are affected by CVE-2026-20127?
CVE-2026-20127 affects the Cisco Catalyst SD-WAN Controller and Cisco Catalyst SD-WAN Manager.
What can attackers do with CVE-2026-20127?
Attackers exploiting CVE-2026-20127 can bypass authentication, potentially gaining access to sensitive configurations.
Is there a workaround for CVE-2026-20127?
While the best solution is to update the software, temporarily limiting network exposure can reduce risk until a patch is applied.