CVE-2026-20247 in Identity Services Engine Software
Summary
by MITRE • 09/16/2026
A vulnerability in Cisco ISE could allow an unauthenticated, remote attacker to conduct SQL injection attacks on an affected device.
This vulnerability is due to improper validation of user-supplied input. An attacker could exploit this vulnerability by sending a crafted request to an affected device. A successful exploit could allow the attacker to modify data in the underlying database.
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Analysis
by VulDB Data Team • 09/16/2026
The identified security flaw resides within Cisco Identity Services Engine, a critical network access control and policy management platform widely deployed in enterprise environments to enforce authentication, authorization, and accounting policies. This specific vulnerability stems from an improper validation of user-supplied input directed at one or more API endpoints or web interfaces managed by the ISE software. The root cause is classified under CWE-89, which denotes Improper Neutralization of Special Elements used in an SQL Command, commonly known as SQL Injection. In this context, the application fails to adequately sanitize or parameterize data provided by external actors before incorporating it into dynamic database queries. This lack of rigorous input validation allows maliciously crafted strings to bypass intended logic and execute arbitrary commands against the underlying relational database management system that stores configuration data, user credentials, policy definitions, and audit logs essential for network security operations.
The operational impact of this vulnerability is severe due to its unauthenticated nature and remote exploitability. An attacker does not require valid credentials or prior access to the ISE administrative interface to initiate an attack. By sending a specially crafted HTTP request containing malicious SQL payloads, an adversary can interact directly with the database backend. A successful exploitation allows the attacker to perform unauthorized data manipulation operations. This includes modifying existing records within the database, which could involve altering security policies, changing user roles or permissions, or corrupting audit trails that are vital for forensic analysis and compliance reporting. Furthermore, depending on the specific configuration of the underlying database server, such as if it runs with elevated privileges like root or sa rights, this vulnerability could potentially be chained to achieve remote code execution, thereby granting full control over the host system running Cisco ISE.
From a threat intelligence perspective, this attack vector aligns closely with MITRE ATT&CK technique T1190, which covers Exploit Public-Facing Applications. The ability to modify data in the underlying database corresponds to techniques under the Impact tactic, specifically Data Manipulation (T1565) and potentially Data Encrypted for Impact if ransomware is deployed following initial access. Because Cisco ISE serves as a central point of trust for network segmentation and identity management, compromising its integrity undermines the entire security architecture it supports. Attackers could use this vulnerability to disable authentication mechanisms, create backdoor accounts with administrative privileges, or exfiltrate sensitive information such as hashed passwords if read operations are also possible through blind SQL injection techniques.
Mitigation strategies must address both immediate remediation and long-term architectural resilience. The primary defense is the application of vendor-provided software updates that patch this specific input validation flaw. Organizations should prioritize upgrading Cisco ISE to a version where this vulnerability has been resolved, as indicated in official security advisories released by Cisco. In scenarios where immediate patching is not feasible due to operational constraints or testing requirements, network-level mitigations can be employed. This includes restricting access to the affected API endpoints and web interfaces using strict firewall rules that limit connectivity only to trusted management subnets. Additionally, deploying a Web Application Firewall with signatures tuned for SQL injection patterns may help detect and block malicious requests before they reach the application layer. It is also critical to ensure that database accounts used by ISE adhere to the principle of least privilege, minimizing the potential damage if an attacker successfully executes arbitrary commands against the database backend. Regular vulnerability scanning and penetration testing focused on input validation weaknesses should be integrated into the security operations lifecycle to identify similar flaws in other components of the network infrastructure.