CVE-2026-20307
Cisco Identity Services Engine Remote Code Execution Vulnerability
Description
A vulnerability in the web-based management interface of Cisco ISE 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 at least low-privileged administrative credentials. This vulnerability is due to insecure deserialization of a user-supplied Java byte stream. An attacker could exploit this vulnerability by sending a crafted serialized Java object 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.
Weakness: CWE-502
Affected products
| Vendor | Product | Category | Matched by |
|---|---|---|---|
| Cisco | Cisco Identity Services Engine (ISE) Check your version | Identity / IAM / MFA | cna-assigner |
Vendor-reported products (1)
- Cisco · Cisco Identity Services Engine Software
Vendor advisory
Cisco Identity Services Engine Remote Code Execution Vulnerabilities
Cisco’s rating: Critical (advisory CVSS 9.9) · Published Sep 16, 2026
Bug IDs: CSCws25575 , CSCwu26102 , CSCwu59400
The vendor’s rating applies to the whole advisory and can differ from this CVE’s own CVSS severity. Where this comes from