Critical severity · published Sep 16, 2026
CVE-2026-20306
Cisco Identity Services Engine Command Injection Vulnerability
9.1
CVSS
1.6%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
High
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)1.6% · higher than 75% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
CI
Cisco ISE Passive Identity Connector · Cisco
3.4.0 · source: vendor
CI
Cisco Identity Services Engine Software · Cisco
3.4 Patch 4; 3.4 Patch 5; 3.5 Patch 3; 3.4 Patch 6 · source: vendor
Affected product
CI
Cisco Identity Services Engine Software
Cisco
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-20306
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-20306
sec.cloudapps.cisco.com
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ise-cmd-inj-e2CuZCYZ
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