---
id: CVE-2026-20352
title: "A vulnerability in the RADIUS feature of Cisco Identity Services Engine (ISE) could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device.\r\n\r\nThis vulnerability is due to improper ha…"
summary: "A vulnerability in the RADIUS feature of Cisco Identity Services Engine (ISE) could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device.\r\n\r\nThis vulnerability is due to improper ha…"
severity: high
cvss: 8.6
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H'
cwe:
  - CWE-119
vendor: Cisco
product: Cisco Identity Services Engine Software
affected:
  - identity_services_engine_software 3.2.0
  - identity_services_engine_software 3.2.0 p1
  - identity_services_engine_software 3.2.0 p2
  - identity_services_engine_software 3.3.0
  - identity_services_engine_software 3.2.0 p3
  - identity_services_engine_software 3.2.0 p4
  - identity_services_engine_software 3.2.0 p5
  - identity_services_engine_software 3.2.0 p6
  - identity_services_engine_software 3.3 Patch 2
  - identity_services_engine_software 3.3 Patch 1
  - identity_services_engine_software 3.3 Patch 3
  - identity_services_engine_software 3.4.0
  - identity_services_engine_software 3.2.0 p7
  - identity_services_engine_software 3.3 Patch 4
  - identity_services_engine_software 3.4 Patch 1
  - identity_services_engine_software 3.3 Patch 5
  - identity_services_engine_software 3.3 Patch 6
  - identity_services_engine_software 3.4 Patch 2
  - identity_services_engine_software 3.3 Patch 7
  - identity_services_engine_software 3.4 Patch 3
  - identity_services_engine_software 3.5.0
  - identity_services_engine_software 3.4 Patch 4
  - identity_services_engine_software 3.3 Patch 8
  - identity_services_engine_software 3.2 Patch 8
  - identity_services_engine_software 3.5 Patch 1
  - identity_services_engine_software 3.3 Patch 9
  - identity_services_engine_software 3.2 Patch 9
  - identity_services_engine_software 3.4 Patch 5
  - identity_services_engine_software 3.5 Patch 3
  - identity_services_engine_software 3.5 Patch 2
  - identity_services_engine_software 3.3 Patch 10
  - identity_services_engine_software 3.3 Patch 11
  - identity_services_engine_software 3.4 Patch 6
  - identity_services_engine_software 3.2 Patch 10
published: '2026-09-16'
updated: '2026-09-18'
sourceUpdated: '2026-09-18T13:28:28.567'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-20352'
references:
  - url: >-
      https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ise-RADIUS-dos-wR3hYPMw
    label: psirt@cisco.com
  - url: 'https://software.cisco.com'
tags:
  - nvd
  - cve.org
  - csaf
  - vendor-advisory
  - cisco
epss: 0.00404
epssPercentile: 0.32027
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-17T16:01:17.414586Z'
ingestedAt: '2026-09-16T16:37:52.184Z'
---

## Overview

A vulnerability in the RADIUS feature of Cisco Identity Services Engine (ISE) could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device.

This vulnerability is due to improper handling of certain RADIUS requests. An attacker could exploit this vulnerability by sending a crafted RADIUS request directly to an affected device. A successful exploit could allow the attacker to cause the ISE node to become unavailable. For single node deployments in that condition, endpoints that have not already authenticated would be unable to access the network until the node comes back up on its own.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **cisco-sa-ise-RADIUS-dos-wR3hYPMw** · Cisco · affected: Cisco Identity Services Engine Software (34 versions) · updated 2026-09-16 · [advisory](https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ise-RADIUS-dos-wR3hYPMw)