CVE-2026-20127

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.

CVSS v3 vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Weaknesses (CWE)

CWE-287

Threats tracking this CVE

• Cisco Catalyst SD-WAN Zero-Day (CVE-2026-20127) — UAT-8616 Active Exploitation Since 2023, Authentication Bypass to Admin, Critical Infrastructure Targeting — CRITICAL

References

• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sdwan-rpa-EHchtZk
• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-20127

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