---
id: CVE-2026-20283
title: "A vulnerability in the IPsec Open API endpoint of Cisco ISE could allow an authenticated, remote attacker to inject arbitrary commands on the underlying operating system. \r\n\r\nThis vulnerability is due to insufficient validation of u…"
summary: "A vulnerability in the IPsec Open API endpoint of Cisco ISE could allow an authenticated, remote attacker to inject arbitrary commands on the underlying operating system. \r\n\r\nThis vulnerability is due to insufficient validation of u…"
severity: medium
cvss: 6.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N'
cwe:
  - CWE-78
vendor: Cisco
product: Cisco Identity Services Engine Software
affected:
  - identity_services_engine_software 3.3.0
  - 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 3.3 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 3.5 Patch 1
  - identity_services_engine_software 3.3 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
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-2026-20283'
references:
  - url: >-
      https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ise-mult-vul-ymSsTLCc
    label: psirt@cisco.com
  - url: 'https://software.cisco.com'
tags:
  - nvd
  - cve.org
  - csaf
  - vendor-advisory
  - cisco
epss: 0.00435
epssPercentile: 0.35151
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-09-17T03:57:40.682633Z'
ingestedAt: '2026-09-16T16:37:52.198Z'
---

## Overview

A vulnerability in the IPsec Open API endpoint of Cisco ISE could allow an authenticated, remote attacker to inject arbitrary commands on the underlying operating system. 

This vulnerability is due to insufficient validation of user-supplied input in IPsec Open API calls. An attacker could exploit this vulnerability by sending crafted input to the IPsec Open API endpoint on an affected device. A successful exploit could allow the attacker to execute arbitrary commands on the underlying operating system. 
To exploit this vulnerability, the attacker must have valid administrative credentials and the node must have more than one network interface, one of which must be configured as an active IPsec tunnel.
Note: For CVE-2026-20283, Cisco has assigned a Security Impact Rating (SIR) of High rather than Medium as the score indicates. The reason is that it is easy to get to root from the achieved privilege level.

## Remediation

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

## Vendor advisories

- **cisco-sa-ise-mult-vul-ymSsTLCc** · Cisco · affected: Cisco Identity Services Engine Software (23 versions) · updated 2026-09-16 · [advisory](https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ise-mult-vul-ymSsTLCc)