← Back to Vulnerability Reports CVE Intelligence

CVE-2026-20127

Cisco Catalyst SD-WAN Controller And Manager•CRITICAL · CVSS 10• In the wild In CISA KEV

What is CVE-2026-20127?

A vulnerability in the peering authentication in 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, 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.

CVSS10 NVD 3.1

SeverityCRITICAL

Exploitation In the wild In CISA KEV

EPSS89% · P100

Triage statusActive Exploit

ActionPatch immediately

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

CWECWE-287

NVD published2026-02-25

NVD last modified2026-06-17

Timeline

2026-02-25Published to the U.S. National Vulnerability Database (NVD)
2026-02-25Added to the CISA Known Exploited Vulnerabilities (KEV) catalog
2026-02-27CISA federal remediation deadline (BOD 22-01)
2026-06-17NVD record last updated

CISA Known Exploited Vulnerability

Cisco Catalyst SD-WAN Controller and Manager Authentication Bypass Vulnerability

Added to KEV2026-02-25

Federal patch deadline2026-02-27

Known ransomware useUnknown

Affected product

Cisco Catalyst SD-WAN Controller And Manager

NVD also lists CPE entries for: Cisco Catalyst Sd-Wan Manager, Cisco Sd-Wan Vbond Orchestrator, Cisco Sd-Wan Vsmart Controller

Remediation Steps

Apply the vendor patch from Cisco for SD-WAN Controller authentication-bypass vulnerability
Restrict administrative access to SD-WAN Controllers to trusted networks only
Monitor Controller logs for unauthorized authentication attempts or privilege escalation
Audit SD-WAN configurations and access credentials for signs of compromise
Escalate to network security and incident response teams for verification in high-security environments

References

Referenced in our briefings & reports

Vulnerability Priority Report – Week 4 of October 2026 (October 26 – November 1)

Related vulnerabilities

CVE-2026-20182 – Cisco Catalyst SD-WAN (same product)
CVE-2026-20245 – Cisco Catalyst SD-WAN Manager (same product)
CVE-2026-76504 – Cisco Catalyst SD-WAN Manager (same product)
CVE-2026-20262 – Cisco Catalyst SD-WAN Manager (same product)
CVE-2026-76418 – Cisco Secure Firewall ASA Software And Cisco Secure FTD Software (same vendor)
CVE-2026-76519 – Cisco Secure Email Gateway (same vendor)

Cisco: 101 known exploited vulnerabilities (CISA KEV) →

Browse all tracked CVEs in the defend.network CVE database →

🤖 This CVE page is generated by defend.network from NVD, CISA KEV, EPSS, and our verified daily briefings. Severity and exploitation data come from official sources; always verify remediation steps against the official vendor advisory before acting in production.