CVE-2026-20284 in Identity Services Engine Software
Summary
by MITRE • 09/16/2026
A vulnerability in the SXP REST API of Cisco ISE could allow an authenticated, remote attacker to conduct SQL injection attacks.
This vulnerability is due to insufficient validation of user-supplied input in REST API calls. An attacker could exploit this vulnerability by sending crafted input to an affected device. A successful exploit could allow the attacker to view or modify data on the underlying database for the affected device. In single-node deployments, successful exploitation of this vulnerability could cause the affected ISE node to become unavailable, resulting in a DoS condition. In that condition, endpoints that have not already authenticated would be unable to access the network until the node is restored. To exploit this vulnerability, the attacker must have valid administrative credentials, have the SXP service enabled, and have at least one SXP connection configured.
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Analysis
by VulDB Data Team • 09/16/2026
The Cisco Identity Services Engine (ISE) platform serves as a critical component in modern enterprise security architectures by providing network access control, posture assessment, and policy enforcement. Within this ecosystem, the Security Exchange Protocol (SXP) REST API facilitates communication between ISE nodes and external SXP peers to exchange IP-to-group mappings for scalable trust zone implementation. A significant vulnerability has been identified within this specific interface, classified under CWE-89 as Improper Neutralization of Special Elements used in an SQL Command. This flaw stems from insufficient validation and sanitization of user-supplied input parameters processed by the REST API endpoints responsible for handling SXP configuration data. The technical root cause lies in the application's failure to properly escape or validate special characters before incorporating them into dynamic database queries, thereby allowing maliciously crafted inputs to alter the intended logic of SQL statements executed against the backend database.
The operational impact of this vulnerability is severe due to its potential for both unauthorized data manipulation and service disruption. An authenticated attacker possessing valid administrative credentials can exploit this flaw by sending specially constructed HTTP requests containing embedded SQL injection payloads. Upon successful execution, these payloads enable the attacker to perform arbitrary read operations on the underlying database, potentially exposing sensitive configuration details, user identities, or policy rules that should remain confidential. Furthermore, the vulnerability allows for write operations, meaning an adversary could modify critical security policies, alter access control lists, or inject malicious configurations into the ISE database. This level of compromise effectively undermines the integrity and confidentiality guarantees provided by the identity management system, allowing the attacker to manipulate network segmentation strategies or bypass authentication requirements for other users.
In addition to data exfiltration and modification, exploitation of this vulnerability can lead to a Denial of Service condition, particularly in single-node deployments where high availability is not configured through clustering. By crafting inputs that cause database errors, resource exhaustion, or infinite loops within the query processing engine, an attacker can render the affected ISE node unavailable. In such scenarios, endpoints attempting to authenticate with the network will be unable to establish connections because the central policy decision point has failed. This results in a complete loss of network access for new sessions until the compromised node is restored or restarted, causing significant operational disruption and potential business downtime. The requirement for administrative credentials limits the attack surface compared to unauthenticated vulnerabilities but still poses a substantial risk given that insider threats or compromised admin accounts are common vectors for advanced persistent threats.
To mitigate this vulnerability, organizations must ensure that Cisco ISE software is updated to include the latest security patches released by Cisco Systems addressing this specific SQL injection flaw in the SXP REST API. Access controls should be strictly enforced to limit administrative access only to trusted personnel and privileged service accounts with multi-factor authentication enabled where possible. Network segmentation strategies should restrict direct internet-facing exposure of management interfaces, ensuring that ISE nodes are accessible only through secure out-of-band management networks or protected internal subnets. Additionally, implementing Web Application Firewalls (WAF) with rules tuned for SQL injection patterns can provide an additional layer of defense by detecting and blocking malicious payloads before they reach the application logic. Monitoring logs for unusual database query patterns or failed authentication attempts associated with SXP services can also aid in early detection of exploitation attempts aligned with ATT&CK techniques involving data exfiltration via common protocol channels or unauthorized access to system resources.