CVE-2026-20181: Cisco Identity Services Engine Remote Code Execution Vulnerability
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. This vulnerability is due to insufficient validation of user-supplied input. An attacker could exploit this vulnerability by sending a crafted HTTP request to an affected device. A successful exploit could allow the attacker to obtain user-level access to the underlying operating system and then elevate privileges to root. In single-node deployments, successful exploitation of this vulnerability could cause the affected ISE node to become unavailable, resulting in a denial of service (DoS) condition. In that condition, endpoints that have not already authenticated would be unable to access the network until the node is restored.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Configuration
Enable and require multi-factor authentication for all administrative accounts to reduce the risk of account misuse even if credentials are compromised.
Cisco ISE administrative authentication multi-factor authentication (MFA) = enabled - Configuration
Apply least-privilege principles: remove or restrict unnecessary administrative accounts and ensure day-to-day tasks are performed with non-administrative accounts where possible.
Cisco ISE administrative accounts administrative privilege model = least-privilege - Compensating control
Restrict network access to Cisco ISE/ISE-PIC management interfaces so that only trusted administrative IP addresses/networks can reach the HTTP(S) management ports (use firewall rules, ACLs, or network segmentation).
- Compensating control
Deploy an HTTP request inspection layer (WAF, reverse proxy, or intrusion prevention) in front of ISE to block or log malformed or suspicious crafted HTTP requests targeting the management interface.
- Compensating control
Isolate ISE/ISE-PIC systems on a dedicated management VLAN or network segment not accessible from general endpoint networks to reduce attack surface for crafted HTTP requests.
- Operational
Rotate and force-reset passwords for all administrative accounts; review and terminate any suspicious or idle administrative sessions and audit recent administrative activity.
- Operational
For single-node deployments, ensure you have current backups and a tested restoration/failover procedure so the ISE node can be restored quickly if it becomes unavailable (DoS) after an exploit.
Event History
Frequently Asked Questions
What is the severity of CVE-2026-20181?
The severity of CVE-2026-20181 is rated as critical with a score of 9.1.
How do I fix CVE-2026-20181?
To address CVE-2026-20181, apply the latest security patches and updates provided by Cisco for the affected versions of Cisco Identity Services Engine.
What type of attack is enabled by CVE-2026-20181?
CVE-2026-20181 enables an authenticated remote attacker to execute arbitrary commands on the underlying operating system.
What are the prerequisites for exploiting CVE-2026-20181?
An attacker must possess valid administrative credentials to exploit CVE-2026-20181.
Which software is affected by CVE-2026-20181?
CVE-2026-20181 affects Cisco Identity Services Engine and Cisco ISE-PIC.