Cisco SD-WAN Controller: Auth Bypass via Peering Auth (CVE-2026-20127)
CVE-2026-20127 Published on February 25, 2026

Cisco Catalyst SD-WAN Controller Authentication Bypass Vulnerability
A vulnerability in the peering authentication in Cisco Catalyst SD-WAN Controller, formerly SD-WAN vSmart, and Cisco Catalyst SD-WAN Manager, formerly SD-WAN vManage, 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. 

NVD

Known Exploited Vulnerability

This Cisco Catalyst SD-WAN Controller and Manager Authentication Bypass Vulnerability is part of CISA's list of Known Exploited Vulnerabilities. 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 affec.

The following remediation steps are recommended / required by February 27, 2026: 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 (

Vulnerability Analysis

CVE-2026-20127 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. This vulnerability is known to be actively exploited by threat actors in an automatable fashion. The potential impact of an exploit of this vulnerability is considered to be critical as this vulnerability has a high impact to the confidentiality, integrity and availability of this component.

Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
NONE
User Interaction:
NONE
Scope:
CHANGED
Confidentiality Impact:
HIGH
Integrity Impact:
HIGH
Availability Impact:
HIGH

Weakness Type

What is an authentification Vulnerability?

When an actor claims to have a given identity, the software does not prove or insufficiently proves that the claim is correct.

CVE-2026-20127 has been classified to as an authentification vulnerability or weakness.


Products Associated with CVE-2026-20127

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Cisco Catalyst Sd Wan Manager
 

Affected Versions

Cisco Catalyst SD-WAN Manager:

Exploit Probability

EPSS
2.60%
Percentile
85.39%

EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.