CVE-2026-20182: Cisco Catalyst SD-WAN Controller Authentication Bypass Vulnerability

Severity: critical (CVSS 10.0 v3.1)
Exploited in the wild: yes — in CISA KEV since 2026-05-14
EPSS: 91.8% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-14 · updated 2026-10-26
Weakness: CWE-287

Description

May 2026: This security advisory provides the details and fix information for a vulnerability that was discovered and fixed after the was disclosed in February 2026. This new advisory is for a new vulnerability in the control connection handshaking. The section of this advisory includes Show Control Connections guidance to help with system checks.  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 the 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.

Affected products

Cisco Catalyst SD-WAN Manager: before 20.9.9.1; from 20.10 before 20.12.5.4; from 20.12.6 before 20.12.6.2; from 20.13 before 20.15.4.4; from 20.15.5 before 20.15.5.2; from 20.16 before 20.18.2.2 — fixed in 20.9.9.1, 20.12.5.4, 20.12.6.2, 20.15.4.4, 20.15.5.2, 20.18.2.2
Cisco Sd-Wan Vbond Orchestrator: before 20.9.9.1; from 20.10 before 20.12.5.4; from 20.12.6 before 20.12.6.2; from 20.13 before 20.15.4.4; from 20.15.5 before 20.15.5.2; from 20.16 before 20.18.2.2 — fixed in 20.9.9.1, 20.12.5.4, 20.12.6.2, 20.15.4.4, 20.15.5.2, 20.18.2.2
Cisco Sd-Wan Vsmart Controller: before 20.9.9.1; from 20.10 before 20.12.5.4; from 20.12.6 before 20.12.6.2; from 20.13 before 20.15.4.4; from 20.15.5 before 20.15.5.2; from 20.16 before 20.18.2.2 — fixed in 20.9.9.1, 20.12.5.4, 20.12.6.2, 20.15.4.4, 20.15.5.2, 20.18.2.2

How to fix

Upgrade to a fixed version: Cisco Catalyst SD-WAN Manager 20.9.9.1, 20.12.5.4, 20.12.6.2, 20.15.4.4; Cisco Sd-Wan Vbond Orchestrator 20.9.9.1, 20.12.5.4, 20.12.6.2, 20.15.4.4; Cisco Sd-Wan Vsmart Controller 20.9.9.1, 20.12.5.4, 20.12.6.2, 20.15.4.4. Check the vendor advisory for mitigations.

References

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