Cisco Identity Services Engine input validation

Summaryinfo

A vulnerability described as very critical has been identified in Cisco Identity Services Engine and ISE Passive Identity Connector. Affected by this issue is some unknown functionality. The manipulation results in input validation. This vulnerability is known as CVE-2026-20237. It is possible to launch the attack remotely. No exploit is available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability, which was classified as very critical, was found in Cisco Identity Services Engine and ISE Passive Identity Connector (unknown version). Affected is an unknown code block. The manipulation with an unknown input leads to a input validation vulnerability. CWE is classifying the issue as CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco Identity Services Engine (ISE) and Cisco ISE Passive Identity Connector (ISE-PIC), engineering teams have conducted a comprehensive internal security review. This review resulted in a software hardening release that addresses multiple internally discovered vulnerabilities. The vulnerabilities tracked by CVE-2026-20237 are related to improper input validation issues that are grouped under the Common Weakness Enumeration (CWE) Pillar CWE-20.

The advisory is available at sec.cloudapps.cisco.com. This vulnerability is traded as CVE-2026-20237 since 10/08/2025. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation requires an enhanced level of successful authentication. The technical details are unknown and an exploit is not available. The structure of the vulnerability defines a possible price range of USD $5k-$25k at the moment (estimation calculated on 09/16/2026).

Upgrading eliminates this vulnerability.

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Productinfo

Type

• Policy Management Software

Vendor

• Cisco

Name

• Identity Services Engine
• ISE Passive Identity Connector

License

• commercial

Website

• Vendor: https://www.cisco.com/

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