Cisco has released fixes for a critical-severity command execution vulnerability in Identity Services Engine (ISE) and ISE Passive Identity Connector (ISE-PIC).
Tracked as CVE-2026-20181 (CVSS score of 9.1), the issue exists because user-supplied input is improperly validated, allowing an attacker to send a crafted HTTP request and obtain user-level access to the underlying operating system. The attacker could then elevate their privileges to root.
“A vulnerability in Cisco ISE and ISE-PIC could allow an authenticated, remote attacker to execute arbitrary commands on the underlying operating system of an affected device. To exploit this vulnerability, the attacker must have valid administrative credentials,” Cisco explains.
In single-node deployments, an attacker could exploit the flaw to cause a denial-of-service (DoS) condition, preventing endpoints that have not already authenticated from accessing the network until the node is restored.
The bug was addressed with the release of ISE and ISE-PIC versions 3.3 Patch 11 and 3.4 Patch 6. A hotfix for ISE version 3.5 is also available and will be included in version 3.5 Patch 4 in August.
