RCE in Cisco Identity Services Engine Software

CVE-2026-20305

A vulnerability in the diagnostic tools of Cisco ISE and ISE-PIC could allow an authenticated, remote attacker to perform command injection attacks on the underlying operating system and elevate privileges to root. To exploit this vulnerability, the attacker must have valid administrative credentials. This vulnerability is due to improper validation of user-supplied input. An attacker could exploit this vulnerability by sending crafted commands to the web-based management interface of an affected device. A successful exploit could allow the attacker to execute arbitrary code on the device and 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.

Vulnerability class: Command Injection (OS Command Injection)

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-20305?
CVE-2026-20305 is a critical-severity vulnerability in Cisco Identity Services Engine Software, classified under OS Command Injection. CVSS score: 9.1/10. Published 2026-09-16.
How severe is CVE-2026-20305?
Critical severity. CVSS v3 base score is 9.1 out of 10.