CVE-2026-20307

Cisco Identity Services Engine Remote Code Execution Vulnerability

Severity
Critical 9.9
CVSS 3.1
Exploited
Not listed
EPSS
0.010
59.9th percentile
Discovered by
Third party
Vendor-published field
Published
Sep 16, 2026
Assigned by cisco

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) Identity / IAM / MFA cna-assigner
Vendor-reported products (1)
  • Cisco · Cisco Identity Services Engine Software

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