CVE-2026-20123 in Evolved Programmable Network Manager
Summary
by MITRE • 02/04/2026
A vulnerability in the web-based management interface of Cisco Evolved Programmable Network Manager (EPNM) and Cisco Prime Infrastructure could allow an unauthenticated, remote attacker to redirect a user to a malicious web page.
This vulnerability is due to improper input validation of the parameters in the HTTP request. An attacker could exploit this vulnerability by intercepting and modifying an HTTP request from a user. A successful exploit could allow the attacker to redirect the user to a malicious web page.
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Analysis
by VulDB Data Team • 03/11/2026
The vulnerability identified as CVE-2026-20123 represents a significant security weakness in Cisco's Evolved Programmable Network Manager and Prime Infrastructure web-based management interfaces. This flaw exists within the authentication and authorization mechanisms of these network management platforms, which are critical components for enterprise network operations and monitoring. The affected systems are widely deployed across enterprise networks, making this vulnerability particularly concerning as it could potentially compromise the integrity of network management operations and expose organizations to various downstream security risks.
The technical root cause of this vulnerability stems from inadequate input validation within the HTTP request processing logic of the web interfaces. Specifically, the systems fail to properly sanitize or validate parameters received in HTTP requests, creating an opening for attackers to manipulate request parameters. This type of vulnerability maps directly to CWE-20, which describes "Improper Input Validation" as a fundamental weakness in software design that allows malicious inputs to bypass validation checks and potentially execute unintended operations. The vulnerability manifests when the web application processes user-supplied parameters without sufficient validation, enabling attackers to inject malicious content that could alter the application's intended behavior.
The operational impact of this vulnerability extends beyond simple redirection attacks, as it creates a potential vector for more sophisticated social engineering campaigns and phishing operations. An attacker exploiting this vulnerability could redirect authenticated users to malicious web pages that appear legitimate but are designed to steal credentials, install malware, or conduct further reconnaissance. The unauthenticated nature of this attack means that no prior access credentials are required to initiate the exploitation process, making it particularly dangerous for network administrators who frequently interact with these management interfaces. This vulnerability aligns with ATT&CK technique T1566, which covers "Phishing" and related social engineering tactics that leverage web-based attack vectors to compromise user systems.
Organizations utilizing Cisco EPNM and Prime Infrastructure should implement immediate mitigations to address this vulnerability. The primary recommendation involves implementing strict input validation controls at all entry points of the web interface, including thorough parameter sanitization and validation before any processing occurs. Network administrators should also consider implementing web application firewalls to monitor and filter suspicious HTTP requests, as well as establishing network segmentation to limit access to these management interfaces. Additionally, organizations should conduct comprehensive security assessments of their network management infrastructure to identify any other potential input validation weaknesses that could be exploited in similar fashion. The vulnerability demonstrates the critical importance of proper input validation in web applications and serves as a reminder of the potential consequences when such fundamental security controls are insufficiently implemented.