CVE-2026-20352

High

Description

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.

SeverityHigh
CVSS8.6
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 Software3.2.0, 3.2.0 p1, 3.2.0 p2, 3.3.0, 3.2.0 p3, 3.2.0 p4, 3.2.0 p5, 3.2.0 p6, 3.3 Patch 2, 3.3 Patch 1, 3.3 Patch 3, 3.4.0, 3.2.0 p7, 3.3 Patch 4, 3.4 Patch 1, 3.3 Patch 5, 3.3 Patch 6, 3.4 Patch 2, 3.3 Patch 7, 3.4 Patch 3, 3.5.0, 3.4 Patch 4, 3.3 Patch 8, 3.2 Patch 8, 3.5 Patch 1, 3.3 Patch 9, 3.2 Patch 9, 3.4 Patch 5, 3.5 Patch 3, 3.5 Patch 2, 3.3 Patch 10, 3.3 Patch 11, 3.4 Patch 6, 3.2 Patch 10—

Check your version

Choose the product and enter the version you run to see whether it falls in the affected range.

In the Intelligence 360 plan

Attack Surface Management

See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.