CVE-2026-20352 PUBLISHED

Cisco Identity Services Engine RADIUS Denial of Service Vulnerability

Assigner: cisco
Reserved: 08.10.2025 Published: 16.09.2026 Updated: 16.09.2026

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.

Metrics

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
CVSS Score: 8.6

Product Status

Vendor Cisco
Product Cisco Identity Services Engine Software
Versions Default: unknown
  • Version 3.2.0 is affected
  • Version 3.2.0 p1 is affected
  • Version 3.2.0 p2 is affected
  • Version 3.3.0 is affected
  • Version 3.2.0 p3 is affected
  • Version 3.2.0 p4 is affected
  • Version 3.2.0 p5 is affected
  • Version 3.2.0 p6 is affected
  • Version 3.3 Patch 2 is affected
  • Version 3.3 Patch 1 is affected
  • Version 3.3 Patch 3 is affected
  • Version 3.4.0 is affected
  • Version 3.2.0 p7 is affected
  • Version 3.3 Patch 4 is affected
  • Version 3.4 Patch 1 is affected
  • Version 3.3 Patch 5 is affected
  • Version 3.3 Patch 6 is affected
  • Version 3.4 Patch 2 is affected
  • Version 3.3 Patch 7 is affected
  • Version 3.4 Patch 3 is affected
  • Version 3.5.0 is affected
  • Version 3.4 Patch 4 is affected
  • Version 3.3 Patch 8 is affected
  • Version 3.2 Patch 8 is affected
  • Version 3.5 Patch 1 is affected
  • Version 3.3 Patch 9 is affected
  • Version 3.2 Patch 9 is affected
  • Version 3.4 Patch 5 is affected
  • Version 3.5 Patch 3 is affected
  • Version 3.5 Patch 2 is affected
  • Version 3.3 Patch 10 is affected
  • Version 3.3 Patch 11 is affected
  • Version 3.4 Patch 6 is affected
  • Version 3.2 Patch 10 is affected

Exploits

The Cisco PSIRT is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.

References

Problem Types

  • Improper Restriction of Operations within the Bounds of a Memory Buffer cwe