CVE-2026-76423 describes a critical security vulnerability in the REST API of Cisco Identity Services Engine (ISE) and Cisco ISE-PIC. The REST API is exposed without adequate authorization checks, allowing unauthenticated remote attackers to send crafted HTTP requests to the API port. This can result in the attacker obtaining administrative access to the device, enabling them to read and modify sensitive configuration and identity data. The vulnerability has a CVSS 3.1 base score of 10.0, reflecting its critical impact with network attack vector, no required privileges or user interaction, and complete confidentiality, integrity, and partial availability impact.

Exploitation of this vulnerability allows unauthenticated remote attackers to gain full administrative privileges on affected Cisco ISE and Cisco ISE-PIC devices. This includes the ability to read and modify configuration and identity data, potentially compromising the security posture of the network environment relying on these devices.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Since no patch or official fix information is provided, organizations should monitor Cisco's security advisories closely for updates. Until a fix is available, restricting access to the REST API port and implementing network-level controls to limit exposure may reduce risk.