External risk intelligence

Cisco ISE Command Execution and Privilege Escalation Vulnerability

CVE advisorySeverity: CRITICAL (CVSS 9.1)

CVE-2026-20181

A vulnerability in Cisco Identity Services Engine (ISE) and ISE-PIC allows authenticated attackers with administrative credentials to execute arbitrary commands on the underlying operating system. This could lead to unauthorized access, privilege escalation to root, and potentially a denial of service impacting network

Path Traversal

Halo Surface Signal

Likely · external exposure

4Halo Surface Signal

Cisco ISE is a network security policy management platform that is frequently deployed as a gateway or edge-adjacent service to manage authentication and network access. While exploitation requires administrative credentials, the product itself is designed to interface with network traffic and management consoles that are often accessible to administrators across the network.

Horizon Alert

Summary of the vulnerability and why it matters

A critical vulnerability has been identified in Cisco Identity Services Engine (ISE) and ISE-PIC, which could allow a privileged user to run unauthorized commands on the system, potentially leading to unauthorized access or denial of service. The main concern is confirming relevance and exposure to our environment.

  • Attackers could gain system control with admin access.
  • It impacts network access control and could cause outages.
  • Confirm if Cisco ISE/ISE-PIC is in use and assess exposure.

Attack Path

How an attacker could exploit the issue

An attacker with administrative credentials could send a specially crafted HTTP request to an affected device. This request targets the Cisco ISE platform's insufficient input validation, potentially allowing the attacker to gain user-level access to the operating system and then elevate privileges to root. In single-node setups, this could also lead to a denial of service, preventing new endpoints from accessing the network.

  • Requires administrative credentials for access.
  • Triggered by sending a crafted HTTP request.
  • Risks OS access, privilege escalation, and DoS.

Live Threat

Current exploitation, exposure, and threat context

An authenticated attacker with administrative credentials could execute arbitrary commands on the operating system, potentially leading to user-level access and privilege escalation to root. In certain configurations, this could render the system unavailable, preventing new endpoints from accessing the network.

  • Underlying operating system data.
  • Sending crafted HTTP requests.
  • Loss of network access.

Operational Fix

Recommended remediation, mitigation, and detection steps

Attackers with administrative credentials can exploit this vulnerability to gain unauthorized access and execute commands on the underlying operating system. The first practical steps involve identifying all instances of the affected Cisco ISE technology, confirming their network reachability and business criticality, and then locating the accountable owner to begin a risk-based remediation plan.

  • Ownership: Network and security teams.
  • Verify first: Identify all affected ISE instances.
  • Action: Plan remediation with vendor coordination.

Supplementary metadata

PCI scan relevance

Yes

CVE-2026-20181 — Halo PCI Relevance: Yes. Under typical PCI ASV external scan criteria, this issue may be flagged for scan prioritization.

This CVE allows an authenticated attacker to execute arbitrary commands on the operating system, which can lead to remote code execution and potentially denial of service, requiring remediation for PCI compliance.

Scan-prioritization guidance only—not a PCI DSS certification or ASV attestation.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

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Frequently asked questions

What is Cisco ISE and what is it used for?

Cisco Identity Services Engine (ISE) and ISE-PIC are network security policy platforms. They manage identity and access control, acting as a central hub to authenticate users and devices before granting them network access. These tools are critical for enforcing security policies across corporate environments, often serving as a gateway or edge-adjacent service.

What does CWE-22 mean for CVE-2026-20181?

This vulnerability involves improper input validation. In the context of CVE-2026-20181, the system fails to adequately check data sent via HTTP requests. This weakness allows an attacker to bypass intended restrictions, execute unauthorized commands on the underlying operating system, and potentially escalate their permissions to root access.

How is CVE-2026-20181 triggered?

An attacker triggers this vulnerability by sending a specially crafted HTTP request to an affected device. Crucially, the attacker must already possess valid administrative credentials to initiate this request. Without these administrative permissions, the malicious request cannot successfully exploit the input validation flaw.

Do I need to worry about this if my ISE instance is internal?

Yes. Halo Surface Signal notes that Cisco ISE is frequently deployed as a gateway or edge-adjacent service, meaning the management consoles are often accessible to administrators across the network. Even if your instance is not directly exposed to the public internet, any administrative access across your internal network represents a potential path for exploitation.

What are the first steps for managing CVE-2026-20181?

Start by identifying all instances of Cisco ISE and ISE-PIC within your infrastructure to determine the full scope of potential impact. Once you have a complete inventory, assess the business criticality and network reachability of each device. Coordinate with your network and security teams to locate the accountable owners and begin building a remediation plan based on vendor guidance.

References

Sources and related resources

Primary sources: NVD, CVE.org.

NVDPublished