CVE-2026-20127

The peering authentication mechanism in the affected systems does not function properly, allowing an attacker to send specially crafted network requests without possessing any credentials. Successful exploitation of the vulnerability allows the attacker to log into the Cisco Catalyst SD-WAN Controller as an internal user account with high privileges (non-root). With access to this account, the attacker can access the NETCONF interface, which enables manipulation of the network configuration of the entire SD-WAN infrastructure.

An attacker can gain high-level privileges in the SD-WAN infrastructure without authentication and manipulate network configuration via NETCONF, which may lead to complete takeover of the organization's network control, disruption of its operations, or data leakage.

Patches available from the manufacturer should be applied according to the references (https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sdwan-rpa-EHchtZk). Due to active exploitation of the vulnerability, the update should be performed immediately.

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) — specific versions indicated in the manufacturer's references

Please adhere to CISA’s guidelines to assess exposure and mitigate risks associated with Cisco SD-WAN devices as outlines in CISA’s Emergency Directive 26-03 (URL listed below in Notes) and CISA’s “Hunt & Hardening Guidance for Cisco SD-WAN Devices (URL listed below in Notes). Adhere to the applicable BOD 22-01 guidance for cloud services or discontinue use of the product if mitigations are not available.

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.