By Zeljka Zorz
Publication Date: 2026-02-25 16:58:00
A “highly sophisticated” cyber threat actor has been exploiting a zero-day authentication bypass vulnerability (CVE-2026-20127) in Cisco Catalyst SD-WAN Controller (formerly vSmart), Cisco has announced today.
The vulnerability was reported by Australian Signals Directorate’s Australian Cyber Security Centre, who said that once the vulnerability was exploited, “the malicious actors add[ed] a rogue peer, and eventually gain[ed] root access to establish long-term persistence in SD-WANs.”
“This vulnerability exists because the peering authentication mechanism in an affected system is not working properly,” Cisco explained in the accompanying security advisory.
“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…
