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, 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 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.
| Vendor | Product | Versions |
|---|---|---|
| Cisco | Cisco Catalyst SD-WAN Manager | 20.1.12, 19.2.1, 18.4.4, 18.4.5, 20.1.1.1, 20.1.1, 19.2.099, 18.3.6, 18.3.7, 19.2.0, 19.1.0, 18.4.303, 19.2.098, 18.3.6.1, 18.2.0, 17.2.8, 18.3.3.1, 18.4.0, 18.3.1, 17.2.6, 17.2.9, 17.2.5, 18.4.0.1, 18.3.3, 18.3.0, 19.2.3, 18.4.501_ES, 20.1.2, 19.2.929, 19.2.31, 20.3.2, 19.2.4, 19.2.4.0.9, 20.1.3.1, 20.9, 20.10, 20.11, 20.12, 20.13, 20.14, 20.15, 20.16, 20.18, 26.1 |
Added new affected versions 20.9 through 20.18 and 26.1.
Updated severity from CRITICAL to HIGH and added new affected version 20.3.2.
Updated description with new technical details and added CVE-2026-20182.
Updated exploit availability to true and noted active exploitation of CVE-2026-20182, along with the identification of XenShell as an IOC.
Updated to indicate that CVE-2026-20182 is actively exploited and added new tags and IoCs related to the exploitation.
Initial creation
