External risk intelligence

Cisco Identity Services Engine and ISE-PIC Vulnerabilities Allow Unauthorized Access via Weak Credentials

CVE advisorySeverity: CRITICAL (CVSS 9.9)

CVE-2026-20234

Cisco ISE and its Passive Identity Connector are policy and identity management services typically deployed within internal network segments to manage access control for enterprise infrastructure. While they facilitate authentication, they are generally protected behind internal controls and are not intended to be directly exposed to the public internet in standard deployment patterns.

Cisco Identity Services Engine

3.1.0 to before 3.3.03.3.03.4.03.5.0

Halo Surface Signal: 2 out of 5 — less likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

A security review by Cisco identified vulnerabilities in Cisco Identity Services Engine and its Passive Identity Connector related to insufficiently protected credentials. These issues, tracked under CWE-522, could allow for unauthorized access if exploited. The main concern is confirming relevance and exposure to your environment.

Weakly protected credentials could be exposed.
Protects core network access control systems.
Confirm if your Cisco Identity Services Engine is affected.

Attack Path

How an attacker could exploit the issue

An attacker could begin by gaining low-privilege access to the network. From there, they might target the Cisco Identity Services Engine or its Passive Identity Connector component, which appears to have insufficiently protected credentials. This could allow an attacker to gain administrative control over the system.

Requires low-privilege network access.
Exploits improperly protected credentials.
Enables administrative control.

Live Threat

Current exploitation, exposure, and threat context

The Cisco Identity Services Engine (ISE) and ISE Passive Identity Connector could be at risk due to insufficiently protected credentials. This could allow an attacker to access sensitive information or gain unauthorized control over the system's services when supported by the advisory's conditions.

System credentials could be exposed.
Weak credential protection may allow access.
Unauthorized access to network services.

Operational Fix

Recommended remediation, mitigation, and detection steps

The Cisco Identity Services Engine (ISE) and Passive Identity Connector (ISE-PIC) are typically managed by infrastructure or platform teams responsible for network access control and identity management. The initial step is to identify all instances of these products within your environment, determine their business criticality and external reachability, and then confirm the accountable owner for each deployment before planning remediation.

Infrastructure or platform teams own this.
Verify product reachability and business impact.
Coordinate vendor updates and plan maintenance.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

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Frequently asked questions

What is Cisco Identity Services Engine (ISE) and ISE-PIC?

Cisco ISE is a platform that manages network access control, authentication, and policy enforcement for enterprise environments. The Passive Identity Connector (ISE-PIC) is a component that gathers user identity data from various sources to support these access policies. Both tools are essential for maintaining secure, controlled access to an organization’s network resources.

What does CWE-522 mean for CVE-2026-20234?

CWE-522 refers to vulnerabilities involving insufficiently protected credentials. In the context of CVE-2026-20234, this means the software does not adequately secure the sensitive information used to authenticate users or processes. This weakness can potentially allow an unauthorized party to access credentials that should otherwise be protected, undermining the security of the identity management system.

How can an attacker trigger this vulnerability?

An attacker typically needs low-privilege access to the network to attempt to exploit these credential protection issues. Simply having network reachability is often a prerequisite for this type of attack. The vulnerability is not triggered by standard, authorized administrative actions, but rather by navigating the system in a way that exploits the flawed credential handling.

How relevant is this CVE to my environment?

Cisco ISE and ISE-PIC are generally deployed within internal network segments to manage enterprise infrastructure and are not intended for public internet exposure. Halo Surface Signal notes this as unlikely to be internet-facing; however, you should verify if any instances were inadvertently exposed, as such configurations significantly increase the risk profile.

What should I do first to address this advisory?

Begin by creating a comprehensive inventory of all Cisco ISE and ISE-PIC instances in your environment. Once identified, confirm the specific version of each installation to see if it matches the affected configurations listed in the advisory. Finally, determine who is responsible for managing these systems so they can prioritize planning for necessary software updates.

References

sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-s…

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.