CVE-2026-76466: Cisco Expressway Series Remote Code Execution Vulnerability
A vulnerability in the database service feature of Cisco Expressway Series could allow an unauthenticated, remote attacker with network access to a Cisco Expressway device to execute arbitrary operating system commands as root. This vulnerability is due to the use of persistent cookies. Additionally, there is insufficient validation of client certificates when the TLS Verify Mode is set to Enabled for clustering, which means that client certificates are not validated. An attacker with possession of the cookies could exploit this vulnerability by connecting to the database service and invoking specific remote procedure call (RPC) commands. A successful exploit could allow the attacker to execute arbitrary commands as root on the underlying operating system of an affected device. Note: Cisco Expressway Series refers to Cisco Expressway Core (Expressway-C) devices and Cisco Expressway Edge (Expressway-E) devices.
Affected Software
Event History
Frequently Asked Questions
Which deployments are exposed to this issue?
Cisco Expressway Core (Expressway-C) and Cisco Expressway Edge (Expressway-E) devices are in scope. Exploitation requires network access to the affected Cisco Expressway device and access to the relevant persistent cookies.
What must an attacker have to exploit the vulnerability?
The attacker needs possession of the persistent cookies and network access to the device's database service. They can then invoke specific RPC commands to execute operating system commands as root.
Does enabling TLS Verify Mode for clustering prevent exploitation?
No. When TLS Verify Mode is set to Enabled for clustering, client certificates are insufficiently validated, meaning the client certificates are not validated.