TI-2026-16535 Aliases CVE-2026-20352 GHSA-qwcp-547c-v9v8

Cisco Identity Services Engine RADIUS Denial of Service Vulnerability

MEDIUM 44CWE-119Published 2026-09-16 · Updated 2026-09-17

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: Denial of service
Confidentiality · integrity · availability: None · None · High
Fix status: No fix listed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-119 and the CVSS impact.

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. 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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00573 47th percentileScored 2026-11-07

Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: Yes
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
Cisco	Cisco Identity Services Engine Software	3.2.0; 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	—	No fix listed	CNA

Cisco Identity Services Engine Software VendorCisco Affected 3.2.0; 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 Fixed in — No fix listed CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPE	Versions	Role	Vendor
cpe:2.3:a:cisco:identity_services_engine::::::::	—	—	Cisco

cpe:2.3:a:cisco:identity_services_engine:*:*:*:*:*:*:*:* Versions — — ·Cisco

Remediation

No fixed version listed by the sources yet.

Timeline

2026-10-02 Threatist record created from CVE-2026-20352
2026-10-03 Alias added: GHSA-qwcp-547c-v9v8

References

Other 1

cisco-sa-ise-RADIUS-dos-wR3hYPMw

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TI-2026-53489 Cisco Secure Email Gateway SQL Injection Vulnerability KEVCVSS 3.1CRITICAL 9.8
TI-2026-53488 Cisco Identity Services Engine Authentication Bypass Vulnerability KEVCVSS 3.1CRITICAL 10.0
TI-2026-16388 Cisco Catalyst SD-WAN Controller Authentication Bypass Vulnerability KEVCVSS 3.1CRITICAL 10.0
TI-2026-16344 Cisco Secure Firewall Management Center Software Remote Code Execution Vulnerability KEVCVSS 3.1CRITICAL 10.0

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Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences