RCE in Cisco Identity Services Engine Software

CVE-2026-20147

A vulnerability in Cisco ISE and Cisco 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 ISE 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)

EPSS: 0.117 (95.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.9 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-20147?
CVE-2026-20147 is a critical-severity vulnerability in Cisco Identity Services Engine Software, classified under Command Injection. CVSS score: 9.9/10. Published 2026-04-15.
How severe is CVE-2026-20147?
Critical severity. CVSS v3 base score is 9.9 out of 10.