#VU123273 Improper authentication in Catalyst SD-WAN Controller (formerly SD-WAN vSmart) and Catalyst SD-WAN Manager (formerly SD-WAN vManage) - CVE-2026-20127
Published: February 25, 2026
Vulnerability identifier: #VU123273
Vulnerability risk: Critical
CVSSv4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:A/U:Red
CVE-ID: CVE-2026-20127
CWE-ID: CWE-287
Exploitation vector: Remote access
Exploit availability:
The vulnerability is being exploited in the wild
Vulnerable software:
Catalyst SD-WAN Controller (formerly SD-WAN vSmart)
Catalyst SD-WAN Manager (formerly SD-WAN vManage)
Catalyst SD-WAN Controller (formerly SD-WAN vSmart)
Catalyst SD-WAN Manager (formerly SD-WAN vManage)
Software vendor:
Cisco Systems, Inc
Cisco Systems, Inc
Description
The vulnerability allows a remote attacker to bypass authentication process.
The vulnerability exists due to an error in authentication mechanism. A remote non-authenticated attacker can send specially crafted requests to bypass authentication process and access NETCONF, which would then allow to manipulate network configuration for the SD-WAN fabric.
Note, the vulnerability is being actively exploited in the wild.
Remediation
Install updates from vendor's website.