CVE-2026-20146 in Identity Services Engine
Summary
by MITRE • 07/15/2026
A vulnerability in Cisco Identity Services Engine (ISE) and Cisco ISE Passive Identity Connector (ISE-PIC) could allow an authenticated, remote attacker to perform path traversal attacks on the underlying operating system to either read or delete arbitrary files. To exploit this vulnerability, the attacker must have valid administrative credentials.
This vulnerability is due to improper validation of user-supplied input. An attacker could exploit this vulnerability by sending a crafted HTTP request to an affected system. A successful exploit could allow the attacker to access sensitive files or delete arbitrary files on the affected system.
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Analysis
by VulDB Data Team • 07/15/2026
The vulnerability in Cisco Identity Services Engine and Cisco ISE Passive Identity Connector represents a critical path traversal flaw that enables authenticated remote attackers to execute arbitrary file operations on the underlying operating system. This security weakness stems from inadequate input validation mechanisms within the web-based management interface of these network security appliances. The vulnerability is classified under CWE-22 as Improper Limitation of a Pathname to a Restricted Directory, which directly relates to improper input validation that allows attackers to manipulate file access paths beyond intended boundaries.
Attackers exploiting this vulnerability must first obtain valid administrative credentials, which establishes a baseline authentication requirement for exploitation. However, the presence of path traversal capabilities within the system's HTTP request handling mechanism creates a dangerous combination where legitimate administrative access can be leveraged to bypass normal file system restrictions. The attack vector specifically involves crafting malicious HTTP requests that manipulate directory traversal sequences such as ../ or ..\ to navigate outside of intended directories and access restricted system files.
The operational impact of this vulnerability extends beyond simple information disclosure to include potential data destruction capabilities. Successful exploitation could enable attackers to read sensitive configuration files, authentication credentials, or other critical system resources stored within the ISE environment. Additionally, the ability to delete arbitrary files presents a significant threat to system integrity and availability, potentially compromising network security policies and operational continuity. This vulnerability directly impacts organizations relying on Cisco ISE for network access control and identity management services.
From an ATT&CK framework perspective, this vulnerability maps to T1059.007 for Command and Scripting Interpreter and T1566.001 for Phishing, as attackers can leverage authenticated administrative access to execute malicious operations. The vulnerability also aligns with T1213.002 for Data from Information Repositories, since it allows extraction of sensitive data stored within the system's file structure. Organizations should implement immediate mitigations including applying official Cisco security patches, restricting administrative access through network segmentation, and implementing strict input validation controls at the application layer to prevent similar path traversal attacks.
The root cause analysis reveals that the vulnerability exists in the web application's handling of user-supplied parameters without proper sanitization or validation of directory paths. This design flaw allows attackers to inject malicious path sequences that bypass normal file system access controls, effectively creating a backdoor for unauthorized file system operations. The vulnerability demonstrates how insufficient input validation can create fundamental security weaknesses even when authentication mechanisms are properly implemented. Security teams should conduct comprehensive assessments of all web applications within their environment to identify similar input validation issues and implement proper parameter sanitization techniques to prevent exploitation.
Cisco has released security advisories addressing this vulnerability through firmware updates that include enhanced input validation for file path parameters. Organizations should prioritize patch management activities to ensure all affected systems receive the necessary security updates. The vulnerability serves as a reminder of the critical importance of validating user-supplied input at multiple layers within application architectures, particularly in administrative interfaces where privileged operations are performed. Implementing defense-in-depth strategies including web application firewalls, access control lists, and regular security assessments can help mitigate similar risks across network infrastructure components.
The exploitation of this vulnerability requires minimal technical sophistication beyond basic knowledge of HTTP request construction and path traversal techniques, making it particularly dangerous for organizations with insufficient security monitoring. Network administrators should implement comprehensive logging and monitoring solutions to detect anomalous file access patterns that may indicate exploitation attempts. The vulnerability also highlights the importance of principle of least privilege implementation, where administrative credentials are restricted to necessary functions only, limiting potential damage from successful exploitation attempts.