CVE-2026-20306

Critical

Description

A vulnerability in the REST API 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 DoS condition. In that condition, endpoints that have not already authenticated would be unable to access the network until the node is restored.

SeverityCritical
CVSS9.1
Exploit probability—
ProductCisco Identity Services Engine Software
PublishedSep 16, 2026
First seenSep 16, 2026

How to fix

Sources list no fixed version or patch link for this vulnerability.

Affected products

ProductAffected versionsFixed in
Cisco Cisco Identity Services Engine Software3.4 Patch 4, 3.4 Patch 5, 3.5 Patch 3, 3.4 Patch 6—
Cisco Cisco ISE Passive Identity Connector3.4.0—

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