Vulnerability Description
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 Score
CRITICAL
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Cisco | Catalyst Sd-Wan Manager | < 20.9.8.2 |
| Cisco | Sd-Wan Vsmart Controller | < 20.9.8.2 |
Related Weaknesses (CWE)
References
- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/ciVendor Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-US Government Resource
FAQ
What is CVE-2026-20127?
CVE-2026-20127 is a vulnerability with a CVSS score of 10.0 (CRITICAL). 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, r...
How severe is CVE-2026-20127?
CVE-2026-20127 has been rated CRITICAL with a CVSS base score of 10.0/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-20127?
Check the references section above for vendor advisories and patch information. Affected products include: Cisco Catalyst Sd-Wan Manager, Cisco Sd-Wan Vsmart Controller.