CVE-2026-20180

Critical

Published: 15 April 2026

Published

15 April 2026

Modified

17 April 2026

KEV Added

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Patch

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CVSS Score 9.9 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

EPSS Score 0.0029 52.9th percentile

Risk Priority 20 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-20180 is a critical-severity Path Traversal (CWE-22) vulnerability in Cisco Identity Services (inferred from references). Its CVSS base score is 9.9 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation of Remote Services (T1210); ranked in the top 47.1% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-2 (Flaw Remediation).

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploitation of Remote Services (T1210) and 2 other techniques. What defenders deploy: see the NIST 800-53 controls recommended below.

Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

SI-10 Information Input Validation good match

prevent

Directly addresses the insufficient validation of user-supplied input that enables path traversal attacks via crafted HTTP requests.

SI-2 Flaw Remediation good match

prevent

Requires timely remediation of the known flaw in Cisco ISE through vendor patches to prevent exploitation.

AC-6 Least Privilege partial match

prevent

Limits damage from exploitation by ensuring Read Only Admin credentials do not grant unnecessary privileges for command execution or escalation.

MITRE ATT&CK Enterprise TechniquesAI

T1210 Exploitation of Remote Services Lateral Movement

Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.

attack.mitre.org →

T1059.004 Unix Shell Execution

Adversaries may abuse Unix shell commands and scripts for execution.

attack.mitre.org →

T1068 Exploitation for Privilege Escalation Privilege Escalation

Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.

attack.mitre.org →

Why these techniques?

Authenticated remote path traversal enables arbitrary OS command execution (T1059.004 via Unix Shell on Linux-based ISE), exploitation of remote service (T1210), and facilitates privilege escalation to root (T1068).

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

NVD Description

A vulnerability in Cisco Identity Services Engine (ISE) could allow an authenticated, remote attacker to execute arbitrary commands on the underlying operating system of an affected device. To exploit this vulnerability, the attacker must have at least Read Only Admin…

credentials. This vulnerability is due to insufficient validation of user-supplied input. An attacker could exploit this vulnerability by sending a crafted HTTP request to an affected device. A successful exploit could allow the attacker to obtain user-level access to the underlying operating system and then elevate privileges to root. In single-node ISE deployments, successful exploitation of these vulnerabilities could cause the affected ISE node to become unavailable, resulting in a denial of service (DoS) condition. In that condition, endpoints that have not already authenticated would be unable to access the network until the node is restored.

Deeper analysisAI

CVE-2026-20180 is a high-severity vulnerability in Cisco Identity Services Engine (ISE) that enables an authenticated, remote attacker to execute arbitrary commands on the underlying operating system of an affected device. The issue stems from insufficient validation of user-supplied input, classified under CWE-22 (Path Traversal), and carries a CVSS v3.1 base score of 9.9 (AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H). It was published on 2026-04-15.

An attacker with at least Read Only Admin credentials can exploit this vulnerability by sending a crafted HTTP request to an affected ISE device. Successful exploitation grants user-level access to the underlying operating system, allowing subsequent privilege escalation to root privileges. In single-node ISE deployments, exploitation can also trigger a denial-of-service (DoS) condition, rendering the node unavailable and preventing unauthenticated endpoints from accessing the network until restoration.

The official Cisco Security Advisory provides details on mitigation, including available patches and workarounds, accessible at https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ise-rce-4fverepv.